114 Prof. E. Forbes on Fossil Invertebrata from Southern India. 



28. Besides the above-described Ammonites from Pondicherry, there is a frag- 

 ment (represented in PL VII. fig. 9) which at first sight seemed to be a portion 

 of some Scaphite, but which I now beUeve to be a part of the outer whorl of an 

 Ammonite allied to some characteristic oolitic forms {A, Gowerianus for example). 

 The whorl is very narrow, and has a back much wider than its breadth. The sides 

 are ornamented with fine deep simple ribs, narrower than the furrows between them. 

 Some of these ribs proceed without increasing over the back and round to the 

 other side ; others, in the example before us, meet in threes at short but prominent 

 tubercles which are placed at considerable distances from each other along the 

 side of the back. From the dorsal side of each of these tubercles, three or four 

 similar fine ribs spring and run across the back to the opposite tubercle. 



This fragment measures 1 inch across the back and -i%ths of an inch across the 

 whorl. I have named it provisionally Ammonites ? indicus. 



Tliere is a fragment of a very large Ammonite, but undeterminable, among the 

 specimens from Trichinopoly. 



Genus Baculites, Lamarck. 



Of this characteristic cretaceous genus, there are two species in the Pondicherry 

 collection, both distinct from all forms hitherto described. 



I. Baculites vagina, sp. nov. PL X. fig. 4. 



B. testa compressa, angulata, Icevigata, undulata; dorso compresso, angusto, piano, margi- 

 nato ; ventre lato, piano ; lateribus in medio undulato-tuberculatis ; apertura obliqua, sinuata. 



Length of the most entire specimen . . 6 — inches. 



Breadth at mouth 1^^^ inch. 



Breadth of back Oy% inch. 



Breadth of belly 0^-^ inch. 



Thickness at mouth Oy^o inch. 



Breadth at mouth of largest fragment . 2 inches. 



Shell a long scabbard-like sheath, broad at the mouth and gradually taperin 

 compressed at the sides, especially dorsally. The back is very narrow and flat 

 margined along two-thirds of the shell by two very slightly-undulated, obtuse, 

 narrow ridges ; from these, for about a third of the breadth, the sides are smooth, 

 or marked only by oblique lines of growth, but in the centre they are undulated 

 by oblique tubercles, which become less numerous and obsolete as the shell becomes 

 narrower. These tubercles are continued slightly to the margin of the broad flat 

 ventral surface. The mouth is very oblique, being produced dorsally into a lingui- 

 form process. The upper surface of each of the lateral tubercles is often marked 

 by a little group of groove-like striae. The cast is very smooth and its angles 

 very obtuse. 



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