894 THE ANIMAL KINGDOM. 



the Greensand, Loftusia comes from the Carboniferous limestone of British 

 Columbia and Eocene strata in Persia. Fusulina is Carboniferous and 

 Permian ; Orbitoides occurs in Cretaceous strata, in Eocene, where it is very 

 frequent in Nummulitic limestone, whilst in Miocene it is rare. Chalk is a 

 fossilised Globigerina ooze ; in some specimens of it Globigerinae form 90 per 

 cent, at least of the bulk. They are found also in some of the Barbadian 

 marls. The majority of Foraminifera are of moderate size, below \ in. ; 

 many are microscopic ; Cycloclypeus Carpenteri, the largest living species, 

 measures rather more than 2 in. across the disc ; Parkeria and species of 

 Orbitoides and Nummulites attain a diameter of 2 in. ; Loftusia is fusiform 

 and 3 in. long. A symbiotic Zooxanthella has been observed in Globigerina 

 echinoides, brownish cells in a Peneroplis, minute nucleated cells in Orbi- 

 tolites complanata, as well as others of larger size, possessed of a distinct 

 membrane, within which the cell undergoes fission. Diatoms retaining 

 their soft parts have been found by Btitschli in the last-named species. 



Carter has described, under the designation i Testamoebiformia] three organisms 

 from the Gulf of Manaar (between South India and Ceylon), two adherent, creep- 

 ing, with calcareous tests, and of these Holocladina is root-like, Cysteodictyina^ 

 retiform ; the third Ceratestina, with subglobular chitinous chambers connected by 

 stolons. Nothing is known of the living organism. See A. N. H. (5), v. 1880, 

 p. 446. 



The Dactyliporinae, which have been usually classed as Foraminifera, are now 

 regarded as Calcareous Algae ; Brady, ' Report,' &c., Challenger Reports, ix. 



P- 59- 



Structures known as Coccoliths and Rhabdoliths are generally found in Globi- 

 gerina ooze and also fossilised in chalk. A Coccolith consists of a flat disc, or of two 

 concave-convex discs, fitted into one another, composed of Calcium carbonate and 

 an organic basis. A Rhabdolith with the same composition has a rod-like form, the 

 actual shape of the rod varying much. Both occur associated in spherical masses, 

 Coccospheres and Rhabdospheres, which are found floating at the surface of the 

 ocean as well as at the bottom. By some they are regarded as Calcareous Algae ; 

 but it has been suggested that they are not unlike the forms assumed by calcareous 

 matter when precipitated in an organic matrix. See Wallich, A. N. H. (3), viii. 

 1861; (4), xix. 1877; O. Schmidt, SB. Wien. Akad. Ixii. Abth. i, 1870; Carter, 

 A. N. H. (4), vii. 1871 ; Wyville Thomson, 'Voyage of the Challenger,' The Atlantic, 

 London, 1877, i. p. 220-2, figs. 49, 50. 



It may be noted here that the term ' Foraminifera ' was originally employed by 

 D'Orbigny in allusion, not to the pores of the perforate test as is commonly sup- 

 posed, but to the one or more pores in the divisions or septa between the cham- 

 bers in the species known to him. D'Orbigny regarded the Foraminifera as a 

 subdivision of Cephalopoda. See A. Sc. N. (i), vii. 1826, p. 245. 



Brady classifies the Foraminifera as follows : 



Fam. i. Gromidae. Test chitinous; smooth or encrusted with foreign 

 bodies ; imperforate ; with a pseudopodial aperture at one or both extremities ; 

 pseudopodia long, branching, reticulate ; with a single terminal aperture, Lieber- 



