150 Prof. E. Forbes on Fossil Invertebrata from Southern India, 



6. Area trinchinopolitensis, sp. nov. PI. XV. fig. 16. 



A. testa inflate, gibba, subtetragona, abrupte truncata, carinata, angulo obtuso, post angulum 

 subsinuata, sublaevigatd, reliqua testa decussato-striata ; are^ parva, lanceolata, umbonibus pro- 

 minentibus. 



Length li inch. Breadth 3^^ inches. Height ly^ij inch. 



Nearly allied to Area decussata and to its allies. Young shells are striated all 

 over. The hinge presents numerous small radiating teeth in the central portion 

 and four obUque large ones at each side. The posterior muscular impression is 

 strengthened by a ridge. 



Locality, Trinchinopoly and Verdachellum. The specimens from the former 

 place are somewhat wider. 



Genus Pectunculus, Lamarck. 



1. Pectuneulus subauriculatus, sp. nov. PI. XVII. fig. 13. 



P. testa oblique-orbiculari, subauriculata, striis transversis longitudinalibusque ornata, um- 

 bonibus obtusis. 



Length 0|f inch. Breadth Oji inch. 



Shell oblique, rounded, with obsolete ears, the surface marked with striae both 

 ways, the longitudinal striae minute and very regular. It is allied to, but distinct 

 from, the greensand Peetunculus umhonatus. 



Locality, Pondicherry. 



Genus Trigonia, Bruguiere. 



1. Trigonia orientalis, sp. nov. PI. XVIII. fig. 11. 



T. testa transverse suborbiculari-ovata, depressa, postice late subrostrata, concentrice sulcata, 

 plicis intermediis rotundatis, laevigatis, area sublaevigata. 

 Length If inch. Breadth 2 inches. 



Shell roundish ovate, depressed, marked by regular transverse sulcations, which 

 are broader than the elevated smooth ribs which separate them. Theposteal area 

 is smooth, or nearly so. In the specimen figured there are about twenty-five 

 transverse ribs. 



Locality, Pon dicherry 



2. Trigonia sub orbicularis, sp. nov. PI. XVIII. fig. 10. 



T. testa suborbiculari, subaequilaterali, postice late subrostrata, concentrice sulcata, costis 

 intermediis elevatis, laeviusculis, area superne laevigata, prope cardinem transverse striata. 



The sulcations are much narrower and more numerous in this species than in 



