495

II. R E P O R T QI~ T H E

CORALS FROM T H E T E R T I A R Y F O R M A T I O N ~ ¢ OF N O R T H AIYIERICA.

COLLECTED BY MR. LYELL~ A.N'D DESCRIBED BY W', LOI~SDALE~ ESQ.~ F. G. S,

I. Account of Ten Species of POLrPARm obtained from the Miocene Tertiary Formations of North America.

The following is a list of the species :

1. Anthophyllum lineatum Lonsdale. (Caryophyllia lineata Conrad.)

2. Columnaria (?) sexradiata Lonsdale. (sp. n.) 3. Astrea hirtolamellata (?) Michelin. 4. Heteropora (?) tortilis Lonsdale. (sp. n.) 5. Escharina tumidula Lonsdale. (sp. n.) 6. Lunulites denticulata Conrad. 7. Cellepora informata Lonsdale. (sp. n.) 8. Cellepora umbilicata Lonsdale. (sp. n.) 9. Cellepora quadrangularis JLonsdale. (sp. n.)

10. Cellepora similis Lonsdale. (sp. n.)

A. Polyparia Anthozoa.

1. _~ITHOPHYLLUI~I LI'NE/tTU1VI.

Stems conical or cylindrical, short, clustered, outer surface ribbed unequally ; lamell~ numerous, breadth variable, irregularly grouped, sides papillated, edges rugged ; centre union of highly foraminated or reticulated ]amellne; terminal cup deep, very rugged, centre projecting papillae; connecting lamln~e thin ; additional stems produced from germs on the sides or at the base of pre- existing.

Zithodendron Jlexuosum, M.ichelin? Ieonographie Zoophy- tologique, p. 49. pl. 10. f. 2. Caryophyllia lineata, Conrad. MS. label.

This fossil differs essentially from any of the corals originally assigned by Schweigger to Lithodendron*, or any of those to which the term has been applied by English palmontologists t ; it differs also equally from the species of Lamarek's Caryophyllia to

* Beobachtungen, &e. Syt. Table VI. t Phillips, Geol. Yorkshire, part ii. p. 202.

L t ~ 2

496 LONSDALE ON MIOCENE CORALS FRO~I N. A~fERICA.

which Ehrenberg has beneficially restricted tha t g e n u s * ; but it agrees with certain of Schweigger 's A n t h o p h y l l a t , in having the stems connected by intermediate layers, or those to which Ehrenberg has ad- vantageously limited the genus. 3~

A comparison of the American specimens with a fine series of a Touraine coral in :Mr. Lyell 's cabinet, believed to be that figured and de- scribed by M. Michelin, led to the inference, that there was no essential difference ; nevertheless it has been thought advisable to adopt Mr. Con- rad's specific name, lest a student should consider the American or

Anthophyllum lineatum. Near the base of the stem, at a, the free edge of an imperfect con- neetlng plate is given. §

[lqatural Size.]

Touraine fossil as identical with the exist ing Caryophyll ia f l ex - uosa, one of the synonymes given in tile " Ieonographie Zoophy- tologique."

The stems were generally attached to testacea, and for the greater part were closely aggregated, the young being occasionally clustered round the sides of the older. They were frequently cylindrical, but sometimes conical, and differed considerably in the diameter of the superior termination in instances of equal altitude. T h e greatest height was 5 lines, and the greatest diameter of the same stein 4½ lines. The sides of the coral, and the ad- jacent surfaces of the bodies to which it was attached, were coated by a thin layer of animal secretion, indicating that the mantle of the polype or its appendages invested the solid polypidom anal in part the supporting body; but free connecting layers were not so strongly developed as in many of the Touraine specimens of equal dimensions, though probably of greater age.

The young stems were essentially produced from germs, ori- ginated in the investing por t ionsof the polype, and sprung either from the sides of the older, but without any connection with their interior, or from near the base; and they soon attained their full diameter. One terminal cup presented irregularities not unlike those which accompany the subdivisions of Dwdalince, but the evidence was not sufficient, when opposed by very numerous cases in which germs appeared to be the ordinary mode of repro- duction, to warrant the inference that the coral was a true subdi- visional polypidom.

Localities. ~ Petersburg, Will iamsburg.

*~ Die Corallenthiere des rothen Meeres, 1834. and Berlin Trans. 1832. Op. cit. Table VI.

t Op. eit. p. 89. Ehrenberg's characters are, " tubuli larninis mernbranacels (palii al,pendicibus ) laxe ferrumlnatl, ramosi, in interstitiis (stolonibus) gemmipari.

§ For an analogous mode of grouping in a recent species, consult Esper's figure (Pflanzenthiere, Madrep. Tab. 28.) of Ehrenberg's Anthophyllum fasci- culare, the ,4. Esperi of Sehweigger.

LONSDALE ON MIOCENE CORALS FRO~I N. AMERICA. 497

2. COLUMNARIA(?) SEXRADIATA.

Polymorphous; tubes polygonal, divergent; adjacent walls separable, exter nally traversed by indistinct ribs and transverse inequalities ; lamellza variable in width, and simple or grouped, according to age ; interstitial lamln~e not numer- ous ; terminal immature star, sides of lamellze vertical, interspaces wide, open ; terminal mature star shallow, sides of lamellm thickened obliquely, the thicken- ing extending across and closing the interspaces; boundary between stars a slight groove ; centre of column and star a union of lamel]ze ; additional columns interpolated.

, t .~ ~

7 a )~

a. Section of CoIumnar~a sexradlata of the natural size, exhibiting the ten- dency of the columns to separate; and in the centre, irregularities in the structure of tim columns, owing to interference during development.

b. A terminal star enlarged, to show the characters believed to be connected with the final termination of growth.

This fine fossil agrees wi th the COLUM~ARIA of Goldfuss in the s impl lc i ty of the in t e rna l s t ruc ture , ~md in the mode of p roduc ing addi t ional co lumns ; bu t changes in the t e rmina l stars, analogous to those exh ib i ted in the coral u n d e r considerat ion, do not appear to have been not iced in Col. sulcata or the o ther species descr ibed by :Professor Goldfuss ( P e t r e l p. 72.). T h e gener ic de te rmina t ion is the re fo re cons idered doubtful . Corals possibly al l ied to this fossil have been f igured f rom 5Iaes t r i ch t by M. Goldfuss unde r the name of Astrea angulosa (Pe t re f . pl. 23. f. 7.), and f rom the musche lka lk of F r a n c e by ]Yl. Miche l in by the name of Ast. polygonalis (Ieonog. Zoophytol . pl. 3. f. 1.) ; but the A m e r i c a n polypidom is most c lear ly not an Astrea, as l imi ted by E h r e n b e r g , nor does i t belong to any of tha t au thor i ty ' s allicd genera , the mode of r ep roduc t ion be ing most dec idedly not by a subdivis ional process.

T h e spec imens w h i c h w e r e e x a m i n e d va r i ed cons iderably in form, be ing cyl indrical , or lobed, or developed in broad expans ions ; ye t the p lan of g r o w t h was the same in eve ry case, the co lumns rad ia t ing abrup t ly f rom a cen t ra l l ine or i m a g i n a r y axis, and be ing

L L 3

498 LONSDALE ON MIOCENE CORALS FRO]~I N. AMERICA.

of limited length. The finest specimen had a somewhat trape- zoidal form, the greatest breadth being rather more than 6 inches, the greatest width 4½, and the greatest thickness 2. The opposite surfaces were slightly uneven, but perfectly occupied by well-pre- served mature stars, and the edges were slightly lobed or fractured. The greatest range of the columns was about nine lines ; and the width of the terminal stars almost uniformly two lines.

In the lower portion of the most regularly formed tubes, which might be considered as representing an early condition of the coral, there were only twelve very thin slightly curved lamella~, each formed~ however, of two closely united plates, and the arched or flat union of the opposite plates constituted the outer wall. In the lower portion of tubes not regularly developed, the lamellm varied in number, being for the greater part rudimentary, as well as in form and mode of union; but they were relatively very thick, and their biplated composition was perfectly distinct: the outer wall had also considerable dimensions; and the trans- verse lamina~ were greatly contorted. In this portion of both regular and irregular tubes, the sides of the lamell~e and of the inner wall were vertical, and not minutely tuberculated ; and the interspaces were deep and open. As the coral advanced towards maturity, the number of lamellm increased to twenty-four, six of which were simple and rather prominent, and ranged from the periphery to the centre, while between each of these was a group composed of two converging narrow plates with a middle broad one, which extended also to the centre. In this state, the upper edges of the lamell~e and the boundary wall began to thicken, and to be coated with fine papillm ; the interspaces were also con- tracted, but the cup was relatively deep, with slightly tuberculated edges. In what was believed to be the final state of growth, the changes just noticed were much more marked; the six simple broad lamella~ rose distinctly above the others, the papillated layer extended across the interspaces, and had relatively con- siderable thickness (two lines), the depth of the cup was greatly diminished, the boundary of the stars had lost their tubercles, and the separation was almost constantly defined by a well-marked groove. In this state, no line of natural separation between the columns could be detected, the thickening being apparently per- sistent, and regularly developed, conforming to the structure of the stars, the characters of which were uniformly exhibited. These specimens, it should be remarked, indicated clearly that the polypes died long previous to their solid fabrics having been enveloped in mineral matter, fragments of small parasitic testacea being attached to the surface_~ and the exterior as well as the interior being penetrated vertically and obliquely by the vermiform cavities of some existing species of marine animal. They exhibited also the peculiar aspect displayed by existing Antlwzoa, after the death of the animal, over the whole or a portion of a specimen.

Changes somewhat analogous, as respects the obliteration of the terminal cup, occur in a polypidom belonging to the coral rag of

I~ONSDALE ON MIOCENE CORALS FROM N. AMERICA. 499

Steeple Ashton * (England), and believed to be referable to t h e Thamnastrea of Lesauvage. In that fossil, however, there is no columnar structure at any period of growth, but a perfect blending of lamell~e ; and there is no thickening layer. In specimens of Porites pyriformis obtained by l~r. Austen from the Devonian limestones of England, changes equally great with those exhibited by Columnaria ? scxradiata have been noticed ~ ; and the lamellm- tubes of tteliopora ccerulea (De BlainviUe) are at one period totally obliterated by an extension and union of the lamelhe : again, in Pocillopora acuta (Lamarck) the polype cavities, always shallow, are in lower portions of a specimen sometimes perfectly filled up, and occasionally difficult to detect; while in Oculina virginea, the tubes cease after a time to be prolonged, though the intermediate spaces continue to thicken, and finally to extend over the mouths of the tubes : lastly, another case of ob- literation, unattended, as in the Oculina, by any marked changes in the structure of the part occupied by the body of the polype, has been noticed in a specimen of Gemmipora crater ? (De B1.), in which the oldest of the projecting stars were com- pletely buried under a thickened extension of the intermediate reticulated structure. These changes, partly noticed on former occasions, are mentioned, because they are believed to be of great importance in generic, and under modified conditions in specific determinations, and because they do not appear to have claimed sufficient attention.

As respects the reproductive process, it is necessary to premise that not a single indication was observed of a subdivision in a ter- minal star. Cases of interpolated small or young columns were not numerous on the surface of the large flat or conical specimens, on account, it was inferred, of the sudden divergence and restricted growth of the columns having produced few interspaces ; but in conical or lobed specimens, which implied continued growth, young stars were noticed, irregularly crowded between others of greater dimensions, with more or less well-defined lines of separation or partition ; and along the centre of fractional sections similar proofs of interpolation were exposed.

Localities. --Evergreen, James's River, Petersburg ?

3..ASTRE)~ HIRTOLAMELLATA l~Iichelin ? Stars polygonal in close contact, unequal ; lamellse numerous, alternately

broad and very narrow, sides papillated, edges rugged ; centre union of lamell~e ; terminal cup deep, edges of lamellm considerably curved ; boundary between the stars sharp, rugged, no blending of lamella~.

Astrea hirtolamellata Michelin? Iconographie Z o o p h y t o l o - g ique , p. 162. pl. 44. g 5. 1845. ( P a r n e s , G r i g n o n , &c.)

- * See Mr. Lyell's Elements of Geology, 2d edit. il. p. 43. fig. 239. ; also the Astrea favosiotdes of Smith's Strata Identified, Coralline Oolite, fig. 1. ; and PhiUips's Geol. Yorkshire, part i. p. 126. pl. 3. fig. 7. Likewise consult Thamnastrea Lamourouxii, 1VIichelin's Icon. Zoophytologique, p. 109. pl. 25. fig. 3.

t Trans. Geol. Soc. of London, 2nd ser. vol. v. descrip, pl. 58. fig. 4. L L 4

5 0 0 LONSDALE ON MIOCENE CORALS FRO~I N. AMERICA.

T h e fossil re fe r red doubtful ly to :M. :Michelin's species consisted of a ser ies of young stars a t tached to a Balanus, and therefore did not exhib i t an equ iva len t s tate of deve lopment to the specimen f igured by tha t au tho r i t y ; but the gene- ral resemblance be tween the corals was too g rea t to justify the proposing a dis t inct specific name.

T h e "American fossil p resen ted appa- r en t ly only one condit ion of growth, the t e rmina l cups pene t ra t ing to the th in base- layer which coated the surface of the Ba- lanus, and there was scarcely a trace of in ters t i t ia l laminae; the na r row lamellm were also very indis t inc t on the lower side of the walls. The specimen never - theless displayed different degrees of de-

r

Astrea hirto-lamellata. Near the point indicated by the letter (a) is an im- perfect star, due apparently to a subdivisional process in the fully developed star next to it.

[Natural Size.J

velopment , in consequence of the product ion lateral ly of addit ional stars. I n the more ma tu re stage the walls had a re la t ively consi- derable elevation, and the broad lamell~e a grea t regular i ty of c h a r a c t e r : there was, moreover , among these stars an impor tan t ins tance of a young one, due, i t was believed, to a subdivisional process. I n the less mature stage, the walls, t hough equal ly sharp on the upper edge, had much less height , and the broader lamellaz were unequal ly developed. The example of what was considered u subdivided s t a r - a characterist ic of Ehrenbe rg ' s res t r ic ted genus - - i s g iven near the le t ter (a) in the wood-cut, and i t exhibi ts wha t are bel ieved to be satisfactory proofs of its or igin ; the wall on one side being regular ly angular, and l ined wi th a l ternately broad and rud imen ta ry lamellm uni formly developed, whiie on the opposite side the wall is arched, and the re are only two i r regular Israelite-plates.

Locality. ~ Wil l iamsburg .

B. Polyparia Bryozoa.

4. I-IETEROPORA ? TORTILIS. (Sp. n.)

Branched; branches dichotomous, thick, sbort; tubes tong, cylindrical or slightly compressed, sometimes in contact, sometimes slightly separated by in- termediate animal secretions, divergence great ; walls thin, minutely punctured, not separable mechanically ; no transverse diaphragms ; larger tubular openings round or slightly angular, edges sharp, no regular arrangement; smaller open- ings round or angular, often very numerous, occasionally few in number ; addi- tional tubes produced partly in the axis, partly in the lateral portions of the branches.

T h e genus HETEROPORA ~, established by ]~I. de Blainvi l le on

* Ehrenberg's genus Iteteropora (Beitr~/ge, &c~ 1831--1834. and Berlin Trans. 18S2.), founded on a subdivision of Lamarck's Madreporw, was probably proposed about the same time as De Blainville's (Man. d'Actinol. 1830--1834.), but it does not appear to have been adopted.

LONSDALE ON ]~IIOCENE CORALS FROM N. AMERICA. 5 0 1

J ~ - ~ ~ O ~ t l l j l ~ '~

a. t1~eterolPora tortilis. Natura l size. General appearance of the coral, and mode of branching.

b. Portion of the same specimen greatly enlarged, exhibiting characters of the surface, and showing the variable size and circular form of intersected tubes, as well as the distinct walls, and the general appearance of the intermediate matter.

c. Vertical section, greatly magnified, to show the mode of radiation, and of interpolating additional tubes.

three species of Prof. Goldfuss's CERIOPORa~, has not been de- scribed either by its founder or by other authorities with sufficient fulness to enable an opinion to be formed of its coml~lete charac- ters, or of the nature of the minor openings, one of the assigned essential structures; nor does Goldfuss's account of the three species afford satisfactory additional details of peculiarities of composition. An examination of his figures (Petref. pl. 10. f. 3. 5. 9.), as well as those of the two species of Lamouroux's fossil AIilleporce (Exp. Methodiq. pl. 82. £ 7, 8. pl. 83. f. 6, 7.), removed by :M. :Yiilne Edwards to Heteropora (Lamarck, 2nd edit. t. ii.) will, i t is conceived, just i fy the conclusion that the genus consists of tubular corals; and perhaps the inference that the smaller open- ings are the terminations of interpolated immature tubes, in no respect analogous to the fine pores in young branches of _Myria- pora truncata (De Blainville). Should these suppositions be correct, the American fossils would agree with those figured by Goldfuss and Lamouroux to the extent inferred: still there are essential characters-neither noticed nor represented by those au- thorities or others in describing the same fossils, as the existence or not of transverse diaphragms, the nature of the walls of the tubuli, and whether the coral underwent any changes during growth or subsequent to maturi ty ; and without a perfect acquaint- ance with which, generic determinations in this division of poly- parians must be always unsatisfactory. The impossibility of comparing fully the American specimens with the structure of those on which M. de Blainville established his genus tIeteropora, required, therefore, that the assignment should be given with a doubt.

5 0 2 LONSDALE ON MIOCENE CORALS FROM ~N. A]~[ERICA.

The numerical proportions between the large and small open- ings varied greatly, the latter occupying sometimes a considerable part of a limited surface ; but an examination showed that these minor apertures were terminations of young or imperfectly de- veloped tubuli ; every condition, from a minute foramen to a large circular tube, having been observed both on the surface and in sections of the interior ; and in the latter cases small tubuli, repre- sentatives of minute apertures, were noticed gradually attaining, in the range towards the surface, the dimensions of the large circular openings. :No indications were detected of a subdivision within a full-grown tube by a vertical plate ranging part ly or wholly across it, the mode by which additional polype cavities are chiefly pro- duced in Chcetetes ; but in every instance the young tubuli had been developed in spaces due to divergence, and either occupied them wholly, or were embedded in "a pellucid interstit ial matter. The original wall of the tubes, where preserved, presented in transverse sections an opaque white circle, strongly contrasted to the surrounding pellucid matter ; and the smallest as well as the largest opening exhibited the same character ; in vertical or oblique sections a similar layer was also sometimes exposed, minutely, but clearly punctured, the pores penetrat ing likewise into the surrounding intersti t ial substance. :No changes de- pendent upon growth, or upon the cessation of it, were observed.

In at tempting to assign a position in the natural series of 1)oly - paria to the coral under consideration, i t is believed that the characters of the tubuli, the w a n t of internal diaphragms, the structure of the walls, and the mode of developing additional tubes, prove it to belong to the Tubuliporid~ of :M. :Milne Edwards, or the Tubuliporea of M. de Blainville ; and that if it be r ightly assigned to tteter.opora, the genus should be removed from :M. de :Blainville's family of Mille_pora.

JLocalities.--W illiamsburg, :Petersburg.

5. ESCHARINA TUMIDULA. ( S p . n . )

Cells oblong ; rows radiating, divided longitudinally by a furrow, but not se- parable mechanically; no transverse furrow between successive cells ; surface slightly convex, with well-defined, large, round pores ; mouth circular, boundary slightly thickened, two small protuberances on the proximal edge, sometimes a small tooth on each side.

But one condition of growth of this species was noticed, and it is fully represented in the wood-cut. The cells were in general regularly arranged with reference to the individual rows ; but there was no uniformity of disposition as respected the whole surface. Thei r length was about one fourth of a line, and breadth one sixth. The interpolated or additional series sprung from the side of an oral te rminat ion; but from their mode of insertion, they might be considered as having had an independent origin, or having been developed from gem-

Escharina tumidula. [Greatly magnified.j

LONSDALE ON MIOCENE CORALS FROM N. AMERICA, ~ 0 3

mules. In every case, however, the first additional cell had been clearly derived from that in which the regular successive cell did not occupy the whole of the distal termination, there being, in both instances, the same want of a distinct transverse separating line, while between the interpolated and the other pre-existing rows, the regular longitudinal furrow was continued. No signs of accessory foramina or of gemmuliferous (?) vesicles were noticed.

Locality. ~ :Petersburg.

6. LUNULITES DENTICULATA Conrad.

Conical ; cells in alternate rows, oblong externally, interior conical, nearly ver- tical to the two surfaces of the polypidom ; immature state, exterior of cell open or denticulated on the margin, mature, covered; mouth near distal extremity semi-circular when imperfect, circular when perfect ; gemmuliferous (?) cham- ber at distal end of cell, opening round ; concave surface irregular, furrowed, minutely granulated, or punctured ; distance between the two surfaces variable.

a. Lunul l tes dentleulata, magnified four times in linear dimensions. b. Cells greatly enlarged to exhibit the dentieulated edge of the immature

state, and the characters of the chambers between the cells.

Lunuli tes denticulata Conrad. Silliman's Journal, Oct. 1841. (Vol. 41.).

This minute Lunuli te is believed to belong to the species de- scribed, but not figured, by Mr. Conrad ; and for a knowledge of the notice in Silliman's Journal, I am indebted to Mr. Lyell. So far as the only specimen contained in the collection would permit a comparison to be made, it resembled greatly a Lunulite found in the crag of England, and possibly that identified, in the "Annals of Natural His tory" for January, 1844 (p. 18.), with the recent Lun. Owenii of the African coast (Gray's " Spicilegia Zoologica," part i. p. 8. t. 3. f. 15. 1828.) ; but as the published notice of the latter does not afford sufficient means for determining the amount of agreement between the recent and fossil corals, it has been deemed advisable to adopt Mr. Conrad's specific name.

This Lunul i te differed from the species described in the notice on the eocene polyparians (posteh), in the important characters of the cells being arranged alternately, in the total absence of inter-

~04 LONSDALE ON MIOCENE CORALS FRO.~I N. AMERICA.

mediate rows of foramina, and in the occurrence at the distal extremity of each cell of a shallow circular hollow or chamber. These structural differences appear to have a constant dependence upon each other; all the quincuncial species examined by the describer having a similar chamber, and all with parallel rows having intermediate series of large foramina. Moreover, in the published figures of Lunulites with alternate cells, as those of Lun. umbellata given by M. de France (Atlas, Dic. Sc. :Nat.), and copied by M. de Blainville (Man. d'Actinol, pl. 72. f. 1.), the situ- ation of the oral aperture and of the chamber is fairly expressed in the general magnified figure, though less happily in the three separate cells (fig. a ) ; and in the representation of Lun. rhom- boidalis given by Goldfuss (:Petrel pl. 37. f. 7.) the chambers are well delineated and have a strong boundary, but are alluded to in the description as oral apertures. M. Michelin, also, in his account of Lun. intermedia, a quincuncial species, says, "chaque grand pore est accompagn6 d'un plus petit, qui lui est inf~rieurement place." (Icon. Zoophy. p. 75.) In Crag and Touraine Lunulites the arrangement of the cells equally influences the position of the chamber; and in the genus Fenestella * the species with parallel cells have an intermediate row of pores or small chambers; while those with quincuncial series have a chamber analogous in position with that at the distal extremity of the cells of Lunulites. I t has been deemed right to solicit attention to these characters, because they do not appear to have received the consideration they merit ; and because the perfect analogy between the position and nature of the cavities in quincuncial species with the chambers in Eschara and Escharina, supposed to be receptacles for maturing gemmules, may assist in forming a correct opinion respecting the inter- mediate rows of foramina or cavities in JLunulites and Fenestella.

The specimen examined was only 2~ lines in diameter; but it presented many different conditions of the cells. Along the irregular margin were a few round chamber-apertures, with well- defined boundaries, but the plane of the opening was oblique to that of the outer surface of the cells. Similar apertures, occupying a nearly analogous position, occurred over the whole surface of the specimen, and had preserved their characters unaltered, whatever changes the cells had undergone. This invariableness appears to be a property by which the chambers may be always readily dis- tinguished from other structures. The cells immediately suc- ceeding the margin exhibited large central open spaces more or less fringed by projecting points; and the development of the outer covering was apparently cffected, as in other species, very irregularly, the process in some cells towards the margin being more advanced than in others farther from it. In the most matured cases, short of a perfectly continuous surface layer, a small opening was preserved near the distal extremity, not very

~* See Appendix A. (vol. i. ), Fenestella, in Mr. ]VIurehison, M. de Verneuil, and the Count yon Keyserling's work on the Geology of Russia. 1845.

LONSDALE ON MIOCENE CORALS FROM N. A~[ERICA. O05

regular in outline, but which might be considered, in that con- dition, as an oral aperture. In the perfectly closed cells, near the base of the inverted cone, a slightly concave and apparently solid lamina, occupied the whole surface. A_ careful study of the general characters dependent upon the mode of forming this outer layer will, it is believed, be found of service in establishing specific differences among Lunulites, equal to that derivable from the variable manner of producing the equivalent portion in JEschar~ and Escharin~.

In the concave surface, the poinb of chief interest was the irre- gular thickenings, connected, it is believed, with renewals of growth, a feature of common occurrence in quincuncial species, but not yet observed by the describer in those with parallel cells, although M. Michelin has delineated carefully an apparently analogous structure in Lun. urceolata. (Icon. Zoophyt. pl. 46. f. 6. 1845.) Where the renewed growth was supposed to have com- menced, a layer, of animal origin, extended backwards from the previous margin, and coated irregularly the anterior concave sur- face, but with a clear separating line. In other species, which permitted, on account of duplicate specimens, an examination to be made, the thickening layer was easily detached, and its surface was found to be impressed with the structure of that to which it had been added, and without any blending of materials; never- theless, the layer differed not in the arrangement of its component materials (an apparently vertical fibrous or laminated structure) from that which immediately underlaid it, or was directly connected with cells, and secreted by the polypes which occupied them.

Zocality. ~ Williamsburg.

7. CELLEPORA INFORM ATA. ( S p . n . )

Incrusting, compressed globular or irregularly botryo'idal cells, form variable, surface densely porous ; mouth circular or oval, in same plane with surfhce, margin raised, thickened, at proximal edge a narrow plate notched in the cen- tre ; gemmuliferous (?) chamber, on one side of proximal margin of mouth ; walls of cells separable ; vertically .fractured section irregularly columnar ; con- necting foramina near base of walls.

This coral and the next were referred to Cellepora, on account of the irregular manner in which the cells were aggregated, and of the want of uniformity as respected the general surface of the oral terminations; in the situation of the chambers assumed to be destined for maturing the gemmules there was also an agreement, as well as in the absence of all marked changes dependent on extreme age, with Cellepora pumicosa, and allied recent or extinct species. Both fossils, however, presented the peculiarity of the walls of the cells readily separating, and each portion 9 f a fractured specimen exhibited constantly flat, glossy, apparently solid walls, totally unlike the curved surfaces occasionally obtained in fractured sections of Cell. pumicosa : in the characters of the mouth, in its being in the same plane with the surface, however

~ 0 6 LONSDALE ON MIOCENE CORALS FROM N. AMERICA.

a. Por t ion of Ce[lepora informecta magnified four times in linear dimensions, I t exhibits the irregular arrangement of the cells ; the occurrence of semi.glo- bular mouthless cells, and the columnar structure of a fractured section.

b. Cells greatly enlarged, to give the characters of the tubercle near the proximal edge of the mouth, and the position of the gemmuliferous (?) vesicle or chamber. The vertical section shows the unobliterated pores in the surface of inferior cells.

irregular the position of the cell, and in the structure of the outer covering, the resemblance to Eschara or Escharina was much greater than to the typical species of Cellepora ; nevertheless it was deemed advisable to refer the Virginia fossils to that genus provisionally.

In what was considered a series of immature cells, the mode of distribution agreed with that of parasitic Flustrce or Escharinw, the development having arisen from the distal extremity of mature cells; and several successive rows had been produced without the appearance in the first series of a decided commencement of the outer surface. Though there was no difficulty in detaching a frag- ment of one of the minute irregular columns, with a perfect surface on each plane, and consisting of three or four cells uniformly super- imposed, as if developed successively from the underlying one, yet it is conceived that the agreement was only accidental, and that the cells were produced horizontally by means of the foramina situated near the base of the walls. No progressive stages, from the im- mature to the mature state, were observed ; but one of the former had a very narrow porous band, which agreed completely in struc- ture with that of the perfect outer covering. No decided proofs of changes incident upon extreme age were noticed on the general surface of the specimen ; and in the cells which had been over- laid by one or more generations, the mouth was not uniformly filled up, nor were the pores always obliterated or coated over by the flooring of the superimposed cells. Examples of mouthless cells occurred both in the somewhat regular layers, and in those confusedly aggregated, the shape in the former instances being normal, but in the latter globular (see figs. a, b), or of every pos- sible inequality of outline. The gemmuliferous (?) chamber was often wanting ; and where it occurred, it was not always on the

LONSDA.LE ON MIOCENE CORALS FRO~I N. AMERICA. 5 0 7

same side of the mouth. I t was small and shallow, but open, the edge being well defined and slightly thickened. The tubercle beneath the mouth was also not constantly present, consisting sometimes of a slight swelling of the porous surface, but more generally of a small solid boss (b).

L o c a l i t y . - - Petersburg, Virginia.

8. CELLEPORA UMBILICATA. ( S p . n . )

Incrusting ; cells in successive enveloping layers; shape irregularly oval or pyriform ; surface bounded by a row of minute foramina, centre uneven, towards the proximal extremity a large transverse foramen, near the mouth two smaller foramina, in general more or less obliterated ; mouth transversely oval, slightly inclined backwards, margin scarcely raised, not thickened, walls of cells separ- able; vertically fractured section irregularly columnar; connecting foramina near base of wall.

a. Portion of Cellepora umbillca magnified four times in linear dimensions, exhibiting near the edges cells in the earliest state or without the surface cover- ing, and also the columnar character of the cells.

b. Part greatly enlarged, to show the characters of the surface and the fora- mina : it gives also exposed portions of the covering of inferior cells.

In all the leading structural peculiarities this species agreed with the last, except in the slightly inclined position of the mouth ; and the generic assignment must be considered only provisional ; in the minor details, the differences were considerable. The mode of developing additional cells on a nearly uniform level was also the same. 1~o decided gemmuliferous chamber was noticed, but beneath the proximal lip of the mouth a minute indentation was frequently observed ; and in the same position, but chiefly in the underlying layers, a prominent tubercle ; and where this structure occurred, the two smaller foramina were situated at its base. The indentation or tubercle agreed in situation with the chamber or vesicle, armed, when perfect, with a long conical process in Celle- p o r a p u m i c o s a . In general only one row of pores surrounded each outer covering, but occasionally there was an intermingling of foramina, due apparently to defective developments. In the underlying cells the mouth was often obliterated, and the central foramen much contracted or filled up, but the boundary pores generally remained open: there were, moreover, no clear in- dications of external thiekenings dependent upon age.

L o c a l i t y . - - Petersburg.

~08 LONSDALE ON I~IIOCEI~E CORALS FRO~I 1~. .~ERICA.

9. CF.LI.EPORA QUADRA~GULARIS. (Sp. n.)

Incrusting ; cells disposed in concentric layers around numerous eentres, no regularity respecting position of distal extremity ; form quadrangular, bounded by a depressed llne, surface very slightly convex, minutely foraminated ; mouth not uniformly in same plane with exterior of cell, round, large, mat in in gene- ral not raised or thickened, sometimes notched on the proximal edge; occasion- ally on one side of the mouth a large pyriform opening to a gemmuliferous (?) chamber ; walls of cells not separable mechanically ; vertical fracture concentri- cally laminated ; connecting foramlna near the base of the walls numerous.

This coral agreed wi th the two pre- ceding in the general Eschara-like cha- racters of the cells, in the variable position of the distal extremity, in exhi- bit ing no changes or external thicken- ings dependent upon age, and in the situation of the supposed gemmuliferous vesicle or chamber; but it differed in the walls not being separable mechani- cally, fractured surfaces displaying al- most constantly the interior of cells arranged in concentric layers, and not irregular columns detachable s ingly: also in the oral aperture having a less uniformly persistent position with re- spect to the surface plane of the cell, being in some instances terminal, and it resembled in its general characters much more nearly those of the mouth of Cellepora pumicosa.

This fossil attained considerable dimensions, one botryo'idal mass being 4~-inches in width, and 3 in height ; and with the exception of the small B a l a n i around which it was encrusted, and a central cavity, it consisted of

a. Cellepora quadrangulari8 : portion of an outer layer magnified, to exhibit the irre- gular arrangement of the cells as respects the oral termina- tion ; also near the asterisk two rows of immature cells.

b. Greatly enlarged cells, to show more fully the porous structure of the surface, and the characters of the oral aper- tures with the adjacent cham- ber ; the figure includes also a mouth|ess cell.

c. A small section, natural size, to represent generally the concentric layers of cells.

concentric polype-strata enveloping the botryo'idal centres. The individual layers had, however, a limited range. The cells, when unaffected by irregularities of surface, had a nearly quadrangular out l ine; and the mouth was in the centre of the distal extremity, i f unaccompanied by the gemmuliferous (?) vesicle ; but if that structure occurred, it was situated on one side. ~Iany mouthless cells were noticed, both wi th and without the vesicle; but the i r regular i ty of development which prevented the formation of the oral aperture, did not apparently interfere in any manner with the perfect conformation of the opening to the supposed repro- ductive chamber. Indications of the progressive mode of con- structing the cells were not observed; nor, as already stated, were there any signs, either on the surface or subjacent layers, of marked changes or thickenings at tendant upon age. In some cases the mouths had apparently been contracted or filled up, but

LONSDALE ON EOCENE CORALS FROM N. AMERICA. 509

they were generally open; and obliteration of the pores, where it occurred, was probably due chiefly to the infiltration of calca- reous matter. The vesicle, as shown in the woodcut, resembled, in the form of the opening, that of typical Celleporw, but the structure itself was more immersed in the body of the cell.

Localities. ~ Williamsburg, Evergreen.

10. CEL~ErORA s~mrrs. (sp. n.) Lobed or convoluted ; cells globular, confusedly aggregated, surface non-fora-

minated, more or less traversed by reticulated or radiating ridges ; mouth large, circular, terminal ; a large hood-shaped projecting gemmuliferous vesicle.

This coral possessed all the lead- ing characters of typical species of the genus, and it resembled C. pumicosa in the form of the cells, and in the confused mode of aggre- gation: in that species radiating ridges near the junction of the cells may also occasionally be detected, but to a much less extent than in the fossil under consideration. The leading distinction between the fossil and recent polyparians con- sisted in the perfect vesicle of the former, when exhibited in sheltered places, not having a long spinous

Cellepora slmills. The figure represents the general

characters of an outer unprotected surface greatly magnified ; but the vesicle is not given in its perfect state or with the projecting hood ; it exhibits accurately the radiating or reticulating ridges.

process ; and there were other minor peculiarities, as the total absence of a transverse plate near the bottom of the aperture.

Locality. - - Williamsburg.

II. Account of Twenty-six Species of POLrPARIA obtained from the Eocene Tertiary Formation of North America.

The following is a list of these corals : - -

1. Ocellaria ramosa Lonsdale. (sp. n.) 2. Flabellum ? cuneiforme Lonsdale. (AnthophyUum euneiforme

Conrad. MS. label. ) 3. Endopachys alatum Lonsdale. (sp. n.) 4. Dendrophyllia l~vis Lonsdale. (sp. n.) 5. Dendrophyllia ? 6. Cladocora (?) recrescens Lonsdale. (sp. n.) 7. Caryophyllia subdichotoma Lonsdale. (sp. n.) 8. Madrepora tubulata(?) Lonsdale. (Astrea tubulata De

Trance.) 9. 2orites. 10. Tubulipora proboscidea (?) Lonsdale. (Pustulopora probos-

cidea (?) Milne Edwards.) 11. Tubulipora.

VOL. I. M M