Prof. E. Forbes on Fossil Invertehrata from Southern India. 107 



Diameter Oy% inch. 



Diameter of outer whorl 0/g inch. 



Thickness 0/^ inch. 



Shell discoid and extremely compressed, the whorls rapidly increasing in 

 breadth ; the outer one embracing all the others and leaving a small umbilicus. The 

 back is rounded and crossed by exquisitely fine regular and continuous striae, which 

 run along the sides towards the umbilicus, but become obsolete before they reach 

 it At the umbilicus are indications of a few short radiating furrows. Mouth 

 oblong, and most dilated superiorly. Very young shells appear to have been 

 smooth and much thicker in their proportions. 



Chambers very complicated and elegant in their pattern. The lateral lobes four 

 or five, very narrow and long, much-divided, and more or less irregularly trifur- 

 cated at their extremities. The superior lateral extends much beyond the dorsal, 

 and is much wider than the next lateral. The saddles are bifurcated, narrow, and 

 beautifully crenated. The partitions of contiguous chambers encroach upon one 

 another. 



Very near Ammonites semistriatus, D'Orbigny, and some allied species from the 

 Neocomian beds of Castellane. 



Locality, Pondicherry, apparently rare. 



15. Ammonites Yama, sp. nov. PI. VII. fig. 4. 



A. testa compressa, laevigata ?, anfractibus planatis, umbilico angustissimo, dorso compresso, 

 rotundato ; apertura compressa, oblonga. 



Diameter 0-^^2^ inch. 



Diameter of outer whorl Oy'2 inch. 



Median thickness 0^^ inch. 



Shell very much worn in the only specimen in the collection, much-compressed, 

 the sides of the whorls being almost flat, very gently increasing towards the mouth, 

 which consequently has an oblong compressed form, distinguishing it from all the 

 species in the collection. The outer whorl embraces all the others so as to leave 

 but a narrow umbilicus. The chambers are not visible. This species is nearly 

 allied to Ammonites Varuna, but easily distinguished by the peculiar form of the 

 aperture and the equality of the whorls. 



Locality, Pondicherry. 



16. Ammonites Varuna, sp. nov. PI. VIII. fig. 5. 



A. testa discoidea, depressa, laevigata, anfractibus 4 depressis, umbilico angustissimo, pro- 

 fundo ; dorso rotundato ; apertura dilatata, rotundata, subtrigona. 



Diameter Oj% inch. 



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