OP SOUTHEEN INDIA. 43 



of the original materials. Some more species I shall have to mention when speaking of Tlioladomya 

 and Fanopma. It is to be hoped that the attention of palaeontologists will be directed more to the 

 genus Foromi/a, than has been hitherto the case^ for it is really a very important genus among 

 mesozoic Pelecypoda. 



Under M7/a a few species from cretaceous rocks have been described by older authors_, but none 

 of them have been proved to belong to that genus. The same is^ strictly speaking, the case with 

 Jurassic and a few palseozoic species of the so-called M^cb, for their determination as yet only depends 

 upon the external form,, and seems in many cases a very doubtful one. 



Thus we have in the cretaceous deposits Gorhula, Corhulamella, Nemra, Poromi/a, most probably 

 Gorhdomyay and possibly Himella represented ; Sj)Jie7iiopsis, Eucharis, Corhurella^ and Cryptomya may 

 be shown to occur; but no such forms as Tngonia, Sphenia^ Platyodon, and even Mya are as yet 

 distinctly indicated. 



COEBULA, JBrug., 1792, (see p. 35). 

 v/ 1. OouBULA STMATULOiDES, Fovhes, PL XVI, Pigs. 13-14. 



1846. C. striatuloides, Forb., Trans,, Geol. Soc, Lond., VII, p. 141, pi. 18, fig. 14 — idem, auctorum. 

 1847.? C. Goclilearia, d'Orbigny, Pal. of the voy. de 1' Astrolabe, pi. 5, figs. 14-17. 



C. testa ohlonga, postice breviter ao o'ectiiiscule caudata^ crassa, convexa^ 

 timbonibus incurvis, fere centraliter sitis instructa ; valvula dextra majori^ postice 

 oblique carinata^ concentrice confertim striata ; valvula sinistra minori^ prope peri- 

 plieriam striis crassiusculis prcedita. 



Height of the larger valve : its length ... ... ... 0*66 



Thickness of shell : „ ... ... ... 0*44 



The solid structure, the great convexity of the right valve, and its short poste- 

 rior prolongation readily distinguish this species from the European C, striatula, 

 and the small height from C. sub-striatula. The right valve is much more solid 

 than the left one ; it also has the margins strongly bent in towards the latter, which 

 is thinner, considerably smaller, but a little more coarsely striated than the 

 right one. The species is very much like the recent (7. sulcata, Lam., from 

 Senegal. 



D'Orbigny's C. cochlearia is most probably the same species as C. striatuloides, 

 though the figures do not correspond very well. The coarser striation of the left 

 valve is distinctly shown ; but the right valve of striatuloides is finely striated, 

 while D'Orbigny's figure represents it equally, or even more coarsely striated 

 than that of the left valve ; no such form occurs in our collection of the South 

 Indian cretaceous fossils. 



Locality, — In a light coloured sandstone south of Koloture ; rare. A similar 

 but flatter species occurs in the soft sandstones at Streepermatoor, but the specimens 

 are not sufficient for characterizing the species. 



Formation. — Trichinopoly group. 



