18 PROTOZOA— RHIZOPODA phylüm i 



Order 2. FORAMINIFBRA d Orbigny. 



Bhiso^oda usuaüy wUh a lest wJUch is typkaüy cakareous hut may be säkeous 

 or agghdinaled; consisting of one ar mare Chambers ; pseudopodia räiculaU. 



The Foraminifera are for the most pari minnte animals varring in size 

 from a fraction of a mülimetre to several millimetres in length, but may 

 deTelop a t^t several inches across ; these, however, are rare exceptions. A 

 few species occur in fresh or brackisli water, but the great majoritj live in 

 the ocean. They are found at all depths, but are most frequent at moderate 

 depths in the ocean basins, where they form characteristic deposits — the 

 so-called "globigerina ooze." In the vicinity of tropical coral islands many 

 species occur in great abundance. 



The animal itself is a single-celled form with one or many nuclei, as will 

 be later explained The test, in many cases at least^ is really an internal 

 structure, as the thin film of protoplasm which covere it in the perforate 

 forms, and probably in others, is capable of secreting the material of the test 

 to repair fractures and the like. 



nature. Haxley (Journal Jücrosoop. SdaK«, 16&S, VUI. 2^o. Cj, oJmI Haöck^ ^JcZi^iäeiie Zeit- 

 schrift, 1870^ V. 3, p. 18) regarded thon st fiist as poitions of Baikgtiu*, and des%iiated 

 them coecolühs (Fig. 1). The simple^ dialdike varieties, eonTex <m fhe uppcr aide and eoneaxie <m 

 the lower, were tenned dücoUOu (Flg. 1, e) ; whfle tiiose ctNuposed (rf* tvo ckisdj applied di^ks 

 of diffex^oit sizes, resraiblii^ cnff-battons in pvofile, were refened to as ejfoihoUtks (Flg. 1, o, b). 

 Coocolitfas are only risible ander poveis of 800 to 1000 diametezs, and exhilxt, as a ruie, a namber 

 of »mes differing in thrär refnctire indioes, whidi are disposed aboot a än^, double <«- star- 



sha^ed centnl grurale. Fre- 

 qaenüy laige nnmbos of eooeo- 

 liths beoome a^gregxted to- 

 gether in tiie fonn of fireel j 

 sospended ^icmles ar coom- 

 9phtres{¥ie.2). Besides cocco- 

 litlis, oäier minnte, rod-shaped, 

 cakareoos bodiesare siHnetinies 

 Fio.l,a,&.— Cbo(»Itas(qpadlMlifi«)ftomäieAyaatic met with, whidi are ebarac- 



£we and in Profile (^DerHKel^^ ^^^ t«sriüed by a discwdal or craci- 



and in i^ofile(mftera Schmidt). fem ealaigenicnt at «le aid. 



FiolIT— Oieoospfeef«sframtlieAtlaiitieOeeaa(ailwHaeekeI). These are called rluMoUiks 



FIO.S.— ffto&doUlftsfromacAdräticSeaCiftieraSehmidtX AUligiues (Flg. 3), and their nodular 



magnifiedTOOdiametas. aggwgations HuAdmpkerrs. 



WyTille ThomsoD, Gart«- and 

 Murray would identify ooooosidierBB as unJoeUnlar aJ^jae, or as spomigia of algse, whfle iTa^flr«»! 

 crestes for them a special gronp, ** Calcoeytae" and assjgns them provisionally to the Protophytes. 

 Acoocding to Hartlng, howevo-, the ac^icm of anunonia genetated by the deeomponlion of albnmin- 

 ons msttrar hdd in solutiaa in lime saifAuie or lime <^k«de|, canses the s^arstifm out ot minnte 

 calcareons didcs which bear a striking reaamhlanee to oooocdiths. Hcaiee it would appear that 

 the farmaüxm ol exxxs^vdj fine dirided paztides of lime in the sea should take place whesrerer 

 there are decxmiposing slbamiiHms or nitrageooos sabstaaces fwesent, and ibe calcium sol^iate 

 held in Solution in the water beomnes pvedpitated as cahänm csrbonateL 



^ Utoature : dPOrbigmjf, A., Foraminißres fossiles du bassin tertiäre de Yienne. Fluis. 1846. 

 — EhrtiAerg, G. O., Mikrogeokgie, 18S4, and AUiaMlungoi der Preoss. Akad. Wisa., 1839. — 

 SAuUm, Max, lieber den Oiganianus der Pdythalamien. häpaäg, 1854. — Ctefpes/er, W. B., 

 Introductran to the Study of the ForaminiCaa. Bay Sodety, 1862. — Rems», E. A., STumerons 

 Reports in Stzungsberichte da* Wveota Akadonie, from 1860 «mwazds. — Sdkwager, Comrad, 

 Sbggio di nna dasäficaäcme dei F<waminiferL Sollet. Condtato GeoL, 1876l — Bmdy, W. B., 

 MfmograjA of Guboniferons and Pernüan F<»aniinifenL PSiaetmtagrsph. Soc, 1S76. — Bradp, 

 W. B., Beport on the Foruninifera^ Scümt. Besults C3ia]lengia- Exped.. Zodogy, XL, 1884. — 

 Skerbom^ C D., Index to the Gkmera and Spedes of the Fnsmini&n. &^th. Mise ColL. 

 1895, T<d. xxzriL — Egger, J. GL, Fonminiftrraii dar Seeweaer Kreädesehichteai. Sitiber. Bayer. 

 Akad. Wlss., 1909, No. W.—SAeOwiem^ E., Monographie der Fnsulinen. Fslaeontogr. 1908-1912, 

 Tols. It., Ux. 



