OF SOUTHERN INDIA. 215 



116-142. — Meek mentions the following in his Check-list of invert, cretaceous fossils of North 

 America, (Smiths. Misc. Coll., No. 177, 1861^ p. 12), — C. ahrnptum, Colorademe, congeslum, curtnm, 

 Enfalense, liemici/cliim, mediale, muliiradiatnm, Ripleyense, speciosiim, T'ippannm, Arkansense, Brazoense, 

 Ckoctawense , filosum, mttUistnatum , perieniie, rarnm, scitulum, snb-quadratum, Texanum, Spillmani ; 

 tlie last eleven species belong to Protocardium, the others to the sub-genus Acantliocardiuin. Besides 

 these are noticed Papyridea elegantula, hella, (not Card, helium, Con.), protexta, rostrata, and sancfi- 

 mhm ; the first four being referred to the sub-genus Liopistlia, but I have already (p. 208) observed 

 that it appears doubtful whether these forms are correctly placed in the CardiiDjE ; some other 

 externally closely allied species undoubtedly belong to Pholadomj/a, and the same may be the case 

 with these few species. 



143-149. — C. Remondiaimm, Cooperii, Brewerii ; C. (Litvicardium) linteum, annidafum, C. f Pro- 

 tocardium) Placerense and translucidiim are recorded by Gabb from the cretaceous rocks of California 

 (Palajont. Calif., ii, p. 242) . 



150-152. — C. subteiiiiim, Protocardium gamhrinnm, and Firginianum are from the so-called 

 lower eocene beds (see Conrad's Check-list, &c., Smiths. Misc. Coll., No. 200, 1866, p. 6). 



153-154. — C. Columhianum imi. acuticostaficm, d'Orb., (Pal. Am. Merid., pp. 82 and 120) ; the 

 last was first described from beds on Qairquina, said to be tertiary ; it has rather a recent aspect and 

 appears to belong to Cardium proper, but subsequently d'Orbigny (Prod, ii, p. 242,) referred the 

 species to Sen on ien 



155. — C. australimtm, d'Orb., Prod, ii, p. 242, is also from Chili. 



156-157. — C. pedernale and transversale from Texas are stated by Romer to be rather in- 

 sufficiently characterised from existing materials (Kreideb. von Texas mid ihre org. Einschliisse, 

 Bonn, 1852, pp. 49 and 50) ; the former is a Protocardium. 



158-159. — C. sabulosum and C. (Prot.) granuliferiim are described from Mexico by Gabb, (Pal. 

 of Calif., ii, p. 267). For the first a new sub-genus, Granocardium, has been proposed, which 

 appears quite unnecessary, as already mentioned (p. 207). 



160-161. — The Indian species are as follows: — C. incomptum, exulans, productum belong to 

 Tracliycardium ; C. (Acanthocardium) pjiUaium ; C. (Cerasloderma) pilatum; C. (? Pectunculus) 

 acrohiciilatum, Protocardium hillanum, delicatulum, Pondicheriense, altum and hiseotum ; Fragum 

 jnmcwreHS. Of this only C. productum and Protoc. hillanum are identical with European si^ecies. 



Looking at this large list of species of C.iRDHNM from cretaceous rocks, we find that the 

 sub-generic forms Acanthocardium, Pectunculus, and Tracliycardium are the most common ; next 

 comes the peculiar more ancient type Protocardium, and then its close ally Lavicardium ; of Ceraslo- 

 derma there are no more than one-twentieth of the whole number ; of Serripes and Fragum only 

 one or two of each, while Cardium as restricted, LunuUcardium and Hemicardium are not at all 

 represented. As to geographical distribution the list shows that the above noted sub-genera are 

 found wherever cretaceous rocks have been met with, and thus the geographical distribution was 

 then much the same as it is now, of course with the exception of the present arctic regions. 



