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



Part the Second. — Inferences draivn from a study of the Species. 



The total number of species of Invertehrata collected by Mr. Kaye and Mr. Cun- 

 liffe in ancient fossiliferous beds of South-Eastern India, and presented to the 

 Geological Society, is 178, of which 165 are Mollusca, two Articulata, eight 

 Echinodermata, and three Zoophytes. The greater proportion are from Pondi- 

 cherry ; Verdachellum and Trinchinopoly furnishing comparatively few. The 

 deposits at the three places named are connected with each other zoologically 

 by the associations of certain species common to two of them with others found in 

 the third. Thus, Pecten quingueco.status and Panopcea orientalis occur in both 

 Pondicherry and Verdachellum beds ; Voluta cincta at Pondicherry and Trinchi- 

 nopoly ; Chemnitzia undosa and Cardium Hillanum at Verdachellum and Trinchi- 

 nopoly. These identifications are so certain, that there can be no question of the 

 mutual geological relations of the beds and of their being members of one system. 

 In what geological epoch that system should be placed is the first inquiry to which 

 we seek an answer. 



At first glance the assemblage of specific forms in this collection seems very 

 anomalous to the European geologist. Accustomed to regard certain generic 

 forms as decided indications of secondary and others of tertiary age, he sees in 

 these Indian fossils numerous species associated, lying side by side in the same 

 stratum, which if found in separate beds would have led to the inference of their 

 having lived at very different and distant epochs. Thus in the Pondicherry beds 

 we have numerous species of Ammonites, Baculites, Hamites and other genera, 

 distinctly of secondary age, associated with varied forms of Voluta, OUva, Cyprcea, 

 Murex, and other genera which are usually regarded as characteristic of strata of 

 tertiary origin. Indeed the latter so prevail in the Trinchinopoly part of the col- 

 lection, that had it alone been brought to Europe, no other inference could have 

 been drawn from it safely than that the strata at Trinchinopoly were decidedly 

 tertiary. 



When however we examine the whole collection critically — species by species — 

 we find that its tertiary aspect is more in appearance than in reahty. Out of the 

 numerous species in this invaluable collection, very few indeed are described 

 forms. But there are a few well-known European species in it, and every one is 

 cretaceous. It happens fortunately that some of these occur in all three col- 

 lections. In the Pondicherry collection we find Pecten quinquecostatus, one of the 

 most characteristic of cretaceous species ; a Pinna undistinguishable from Pinna 

 restituta ; two beautiful Ammonites {A. Juilleti and A. Rouyanus), between which 



