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



cave umbilicus exposing numerous depressed whorls, usually eight or nine in num- 

 ber. These whorls are furrowed at intervals by deep, oblique and slightly undu- 

 lated furrows of growth, about four of which are seen on the cast of the outer 

 whorl : when the shell is present the furrows are filled up. The surface of the 

 true shell is very finely marked by regular oblique transverse strise, the interstices 

 of which rise into minute ridges like those seen on the epidermis of many Helices, 

 as H. pulchellus. It appears to have been very thin. The back is rounded ; the 

 mouth is slightly reniform and very broad. 



The chambers of this remarkable species are much divided, there being no fewer 

 than five very narrow and gradually decreasing lobes, more or less trifurcated at 

 their extremities. The intermediate saddles are also narrow and are bifurcated. 

 The dorsal lobe is a little shorter than the superior lateral. 



This curious Ammonite, one of the most interesting in the collection, appears to 

 be an extreme form of the group of Ligati. 



Locality, Pondicherry. 



5. Ammonites Garuda, sp. nov. PI. VII. fig. I. 



A. testa discoidea, laevigata, in umbilico radiatim striata ; anfractibus 5, ultimo inflate ; dorso 

 rotundato, umbilico profundo ; apertura rotundata, subinflata. 



Diameter 0^^ inch. 



Diameter of outer whorl 0^^ inch. 



Thickness Oi^ inch. 



Whorls about five, gradually increasing, and the outer one somewhat inflated 

 towards the aperture. The shell appears in some specimens to have been striated, 

 and in others smooth : in the larger specimens radiating striae are seen in the um- 

 bilicus proceeding from the suture of the whorls. 



The chambers are very complicated in old specimens, comparatively simple in 

 young (as figured). The lateral lobes are four, the superior ones bifurcated, their 

 divisions trifurcated. The dorsal lobe, which is as long or longer than the superior 

 lateral, is deeply cleft, the branches slender and trifurcating. The saddles are 

 more or less three-branched, their lobules ovate and very regular. 



Locality, Pondicherry. 



6. Ammonites Soma, sp. nov. PI. VII. fig. 7. 



A. testa discoidea, laevigata, subcompressa, sulcata, sulcis distantibus, anfractibus 4-5, ultimo 

 lato ; umbilico parvo, profundo ; dorso rotundato ; apertura suborbiculari, subcompressa. 



Diameter Oj§ inch. 



Diameter of outer whorl 0y*2 inch. 



Median thickness Oy'^ inch. 



