328 CRETACEOUS PELECYPODA 



NUCULA, Lamarck, 1799, (seep. 325). 



1. NucTJLA TAMULICA, StoliczJca, PI, XVII, Figs. 15-16. 



N. testa ovata, valde incequilaterali, aiitice producta et siih-rotimdata , 2)0stice 

 brevissima, oblique truncata, area applanata et longa instructa, compressiuseula, 

 umbonibits ohtusiusculis, approximatis, incurvis ; snperjlcie coucentrice minute 

 striata, siilcis nonnullis crassioribus ad marginem prcedila. 



Height of shell : its length ... ... ... ... 0-73 



Thickness „ : „ ... ... .;. ... 0'44 



This species belongs to the type of Deshayes' simplex, largely represented in 

 cretaceous rocks, hut distinguished by its perfectly truncated posterior end and 

 flat, or along the middle almost excavated, area. It in this respect resembles 

 N. vox, Gieb., ftcnera, Miill.,) from the Plainer beds at Aachen, but this species 

 is again distinguished by its radiating striatiou, which is always more or less 

 distinctly traceable. 



Localities. — Karapaudy, Comarapolliam, and Olapaudy, in a soft, whitish 

 and coarse sandstone. 



Formation. — Arrialoor group. 



2, NucTJiiA INDEFINITA, Forbcs, PI. XVII, Pigs. 17-19. 



1846. Nucula indefinita, Forbes, Trans. Geol. Soc, Lend., vii, p. 148, (passim). 



N. testa ovata, sub-tiimida, antice siib-rotiindata, snpra ac infra lente curvata, 

 postiee brevissima, truncata,* area mediocri, ptaiilo excavata, hand distincter maryi- 

 nata, iimbonibiis prominnlis ; superficie concentrice minute striata; dentibus cardinis 

 anterioribus circiter 14i, crassis, impressione musculuri postica valde elongata, elevata, 

 marginali. 



Height of shell : its length ... ... ... ... 070 



Thickness „ : „ ... ... ... ... 0-50 



Porbes proposed the name for a small cast of tliis species, very like the one 

 represented in fig. 18, f pi. xvii, which is from Cunlif fe's collection of Pondicherry 

 shells. It is a small species of a slightly more elongated and tumid form than 

 TamiiUca, and has the area shorter, somewhat excavated, and indistinctly margined. 

 The posterior muscular impression is very elongated, marginal, and situated on a 

 thickened plate, forming a deep excavation on the cast. 



Localities. — Pondicherry, in a bluish sandstone ; Ninnyoor, in a white sandy 

 limestone ; only one specimen from each locality was examined. 



Formation. — Arrialoor group. 



* In fig. 17 the inferior end below the lunula is a little too much produced. 



t The beaks should be a little less prominent. . 



