98 CRETACEOUS EOCKS OF S. INDIA. [PaRT II. § 1 . 



specifically examined, and compared with those of the better known 

 formations of Europe, it would be rash to offer any opinion on its Geologi- 

 cal age, beyond that which may fairly be deduced from its generic fades, 

 and from a comparison of that fades with those of the faunas belonging 

 to the associated groups on the one hand, and to the larger formations 

 of Europe on the other. This comparison indicates that, while it is con- 

 siderably newer than the Valudayur group of Pondicherry, which has 

 been referred on good grounds to the Neocomian formation, and is older 

 than two groups which have decidedly upper Cretaceous faunas, it has at 

 the same time a notable community of forms with the lower of these two 

 groups, and a smaller number identical with those of the Valudayur 

 beds. We should thus assign it a position about midway in the Cretace- 

 ous series, and this general conclusion is fully borne out by the characters 

 of the only order I have hitherto examined at all in detail, viz., the 

 Cephalopoda, the forms of which bear most resemblance to those of the 

 Gault and Upper Greensand, with a certain admixture of Neocomian 

 forms. 



With respect to the physical conditions of the formation we are able 

 ^, . , ^.^. c to speak with much greater confidence, the litho- 



Ph}'sical conditions of -"^ ° ' 



the Group. logical and zoological indications on this point 



being numerous. We have seen in the foregoing description that the 



Southern half of the formation consists almost exclusively of fine 



silts, with occasional thin bands of sand, but rarely or never, (except 



in the case of beds immediately around coral-reef ridges, ) including 



anything like a pebble or conglomerate bed. The lowest beds are, 



for the most part, composed of the same fine materials as the bulk of 



the formation. The occurrence of a houlder-bed 



at certain spots does indeed seem at first sight 



to negative this statement, but from the way in which these 



boulders are crowded together, and their interstices filled with fine 



silt similar to that which immediately covers them in thin regular 



