Some Foraminifera from Rathlin IslandAuthor(s): Joseph WrightSource: The Irish Naturalist, Vol. 11, No. 9 (Sep., 1902), pp. 211-213Published by: Irish Naturalists' Journal Ltd.Stable URL: http://www.jstor.org/stable/25522193 .

Accessed: 14/06/2014 21:45

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact support@jstor.org.

.

Irish Naturalists' Journal Ltd. is collaborating with JSTOR to digitize, preserve and extend access to The IrishNaturalist.

http://www.jstor.org

This content downloaded from 91.229.248.154 on Sat, 14 Jun 2014 21:45:02 PMAll use subject to JSTOR Terms and Conditions

IRISH NATURALIST, VOL. XI ] 'PLATE 3

A

B

x x

~~~~~E D

0

FORAMINIFERA

TEXTULARIA AND SPIROPLECTA, SHOWING MODE OF GROWTH.

,To face p 2II

This content downloaded from 91.229.248.154 on Sat, 14 Jun 2014 21:45:02 PMAll use subject to JSTOR Terms and Conditions

1902* gI 1

SOME FORAMINIFERA FROM RATHLIN ISLAND.

BY JOSEPH WRIGHT, PLG.S.

PLATE 3.

DURING several visits to Ballycastle in recent years Messrs. Chaster, Hardy, Standen, and Welch spent some time dredg

ing in Rathlin Sound and Church Bay. As the dredgings

were undertaken with the view of collecting shells only, the

sieves which were used for the washing of the material were

those best fitted for that purpose, and were not fine enough for

retaining organisms so small as Foraminifera. The specimens

found by me in the material consisted for the greater part of

the larger forms, and in all probability nearly all the smaller

ones got washed away with the fine material; this no doubt

is the reason why a number of species usually met with

around the Irish coasts were not found in these gatherings.

One of the most interesting forms met with was Botellina

labyrin/hica. This species had some years previously been found in considerable abundance in a dredging taken about

midway between Belfast Iough and Portpatrick, at a depth of ioo fathoms (1); the only previous record for this fine species

being the Faroe Channel, where it was obtained in some

abundance on the third cruise of the " Porcupine," I869, at a

depth of 440 fathoms (2). It may be here also stated that a very

small but perfect specimen of Frondicularia Millettii was

obtained many years ago in a dredging taken off Portrush.

Both of these species are now recorded as new to the British

fauna. In my report of the Foraminifera of the South-West of Ire

land during the cruise of the "Flying Falcon," i888 (3), I

recorded Tex/ularia sagitiula, Defrance, under the name of Spiroplecta sagitlula. On this occasion the specimens were examined under the microscope with reflected light only, and

(1) Second dredging cruise ss. "Protector," Belfast Nat Field Club,

x886. (s) Brady. "Challenger" Report, p. 280.

(t) Proc. Roy. Irish Acad., i89i.

This content downloaded from 91.229.248.154 on Sat, 14 Jun 2014 21:45:02 PMAll use subject to JSTOR Terms and Conditions

212 the Irish Naturalist. Septemtber,

as the test of this species is subarenaceous, the spiral arrange

ment of the early chambers, which constitutes the difference between Spiroplecta and 7extularia, is not easily seen. This is especially the case with the pointed forms, in which the

early spiral chambers are always extremely minute. I have

since examined with transnmitted light specimens mounted in Canada balsam, and by this means I have been enabled to see

most distinctly the arrangement of the chambers throughout the entire test. I have examined in this way about 150 from

dredgings taken off the Irish coast, including these Rathlin specimens, with a large number of fossil specimens from the

Chalk of Co. Antrim; also the only perfect specimen which I

had of the variety fistulosa, Brady, from Raine Island, Torres

Straits, I55 fathoms. In all cases both the recent and fossil

specimens when perfect had the early chambers arranged in a

spiral manner. Further research since I888 has therefore

confirmed me in my belief that this species is truly a Spiro

Plecda and not a Textularia.

To my friend, Robert Welch, I am greatly indebted for the

very accurate drawings of the Foraminifera which accompany

this communication. The followinig species were from dredgings taken in Church

Bay in from 17 to 22 fathonms:

LIST OF SPECIEs.

BDIocuIIna lrregularie, d'Orb.-Very rare. B. ringens, var. elongatap d'Orb.-Rare.

B. clepressa, d'Orb.-Frequent. Splroloculina excavata, d'Orb.-Frequent. S. canaliculata, d'Orb.-Rare.

Miliolina seminulum (Linn.).-Commnon. rm. oblonga (Montag.).-Very rare.

MI. trigonula (Lamk.).-Rare.

M. secans (d'Orb.).-Rare.

WI. subrotuncla (Montag.).-Rare. Mw. bicornis (W. &J.).-Frequent. Hl. Ferussacli (d'Orb.).-Rare.

mVI. aggiutinans (d'Orb.).-Very rare.

Jaculella acuta, Br.-Frequent,

Hyperammilna arborescensf (Norm,).-Rare.

Botellna labyri nthlca, Br.-Common. Reophax scorplurus, Montf.-Very rare.

R. monXlforme. Siddall.-Rarei specimens large6

This content downloaded from 91.229.248.154 on Sat, 14 Jun 2014 21:45:02 PMAll use subject to JSTOR Terms and Conditions

1902. WRIGHT.-Some toramin ifera from atahlin Asland. 2I3

Haplophragmlum pseudospirale (Will.). -Very rare.

H . canarlense (d'Orb.).-Very rare.. H. globigerlnlforme (P. & J.).-Very rare.

Ammodliscus Incertus (d'Orb).-Very rare.

Textularia gramen, d'Orb.-Common.

Spiroplecta sagittula (Defr.) -Frequent.

Gauctryina ruclls, Wright.-Abundant.

Lagena costata (Will.).-Very rare.

Nodosarla farcimen (Sold.).-Short stout variety, rare.

Vaginullna legumen (Linn.).-Rare.

V. Ilnearis (Montag.)-Rare.

Cristellarla rotulata (Lamk.).-Very rare.

Polyymorphilia gibba, d'Orb.-Frequent. Also fistulose form, rare.

P. compressa, d'Orb.-Rare.

P. rotundata (Born.).-Abundant.

Discorblna globularls (d'Orb.).-Frequent.

Truncatullna refulgens (Montf.).-Abundant.

To Kobatula (W. & J.).-Common.

Pulvinulina repandia (F. & M.).-Common.

P. auricula (F. & M.).-Rare.

Rotalla Beccaril (Linn).-Rare.

Nontonina WmbIlicatula (Montag.).-Very rare.

Gypsina veslcularis (P. & J.).-Frequent.

G. tnherens (Schulze).-Frequent.

Polystomella macella (F. & M.).-Very rare.

P. crlspa (Linn).-Very rare.

EXPI,ANATION OS PLATE 3.

a. Textularia, showing alternate method of growth throughout the

entire test, after d'Orbigny.

b. Spiroplecta, showing the spiral arrangement of the earlychambers, after Ehrenberg.

x. The primordial chamber.

c. Spiroplecta sasittula (Defr.), from chalk powder, Co. Antrm. X 55

d. ,, ,, from ss. "'Lord Bandon " cruise, S.W.

Ireland. x 55.

e. ,, ,, pointed form, from ss. "Lord Bandon"

cruise, S.W. of Ireland. X 70

Belfast.

This content downloaded from 91.229.248.154 on Sat, 14 Jun 2014 21:45:02 PMAll use subject to JSTOR Terms and Conditions