510 CEETACEOUS PELECYPODA OE SOUTHERN INDIA. 



Thus, for instance, Inoc. Cripsianus, JEryph. lenticularis, Bad, tecta, JExog. lacu 

 niata, Oryph, vesicularis, Ost, ungulata, and others are particularly characteristic of 

 the upper cretaceous beds in Europe, and in India they are exclusively found in 

 the Arrialoor beds. On the other hand, Inoc. lahiatus, Vola Icevis, JExog, halio- 

 toidea and sub-orbiculata (^= columha)^ Gryph, vesiculosa^ Ostrea diluviana^ and cari- 

 nata characterize the middle cretaceous beds, chiefly the lower series, and they are 

 restricted to the Ootatoor beds in India. Again, there are some, as Card, productum^ 

 JProtoG. hillanum, Vola quinquecostata^ Pholadomya caudata^ Amus. membranaceum, 

 and a few others, which in Europe occur in the middle and upper series of creta- 

 ceous deposits, and those species maintain a quite similar yertical distribution in 

 India. 



When Prof E. Eorbes first examined the invertebrate fauna of the South 

 Indian cretaceous deposits he expressed himself in favour of their being of Neoco- 

 mien age, the conclusions being apparently chiefly based upon the general character 

 of the Cephalopoda. My first report in Vol. I of Pal. Indica showed that Eorbes' 

 views were untenable, but that there are to all appearance several species of Cepha- 

 lopoda which are identical with others occurring in the Gault of Europe. Subse- 

 quently after my visit to Europe which was undertaken for the purpose of com- 

 paring Eorbes' originals, and similar fossils in other collections, I reduced* a few 

 of the identifications with Gault species, and I dare say, if sufficient materials for 

 comparison were accessible, that number could still be lessened. When reporting* 

 upon the character of the Gastropod fauna (in Vol. II of Pal. Indica), I noticed 

 only three Gastropoda which had a remarkably close resemblance to Gault species, 

 but at the same time I pointed out that the character of the Gastropod fauna is 

 decidedly upper and middle cretaceous. 



The examination of the Pelecypoda has entirely confirmed this view, the more 

 so that I have not been able to identify a single species with one from the Gault. 

 There can be at the present, I believe, no doubt entertained against the view, that 

 the cretaceous deposits of India correspond to the middle and upper cretaceous 

 beds of Europe, namely, the Ootatoor and Trichinopoly groups represent d' Orbigny's 

 Cenomanien and the lower part of the Turonien^ or Coquand's principal divisions 

 Motomagien and Garentonien. The parallel is probably still better with the German 

 ' Plsener.' The Ootatoor beds — with Am.. Motomagensis and rostratus^ Inoceramus 

 labiatus, Exogyra suborbiculata, GrypJi, vesiculosa — evidently represent the lower 

 Plsener ; the Trichinopoly beds, (the fauna of which often does not appear to be very 

 well defined from the previous,) —with Am. perampluSy 8fc.^ may be best identified 

 with the middle Plsener. 



The Arrialoor beds correspond to d'Orbigny's upper part of Turonien and 

 to the Senonien, or to Coquand's chief divisions Santonien and Gampanien. They 

 are also perfectly equivalent to the upper Ptener of German geologists, charac- 

 terized by Amm. Gardeni, Inoceramus Gripsianus, Exogyra laciniatay Gryph. ve&i-- 

 cularis, and many others. 



* Records Geological Survey of India, Vol.. I, p. 32^ &c. 



