Chap. VI.] trichinopoly district — ootatoor groit. 75 



The stratification of tlie Ootatoor Group, although tolerahly reguhar on 



the whole, and exhibiting a general dip to the 

 Stratification. 



South-west, presents many anomalies which lead 



rae to conclude that it is by no means due to regular superposition of sedi- 

 ment deposits on a horizontal sea bottom ; but rather to the banking of 

 successive layers of sedimentary matter ; the dip of which is, with few 

 exceptions, due to the shelving form of the banks on which they were 

 Due to deposition on formed. The reasons which have led me to enter- 

 '^^ "■ tain this view will appear in the detailed description 



of the Geological features of the group, and will be summarised at the 

 end of the section ; and I will not therefore anticipate them by attempting 

 an imperfect outline here ; but the fact, if admitted, iDrecludes the possibi- 

 lity of forming any reliable estimate of the thickness of the group from 

 the merely superficial data afforded by the present condition of the 

 country. 

 The fauna of the group is a subject upon which I can only speak in 



very general terms, and from such knowledge as 

 Fauna of Group. 



can be gathered during a field survey, and from a 



cursory inspection of the fossils at the time of their collection.* The sub- 

 ject is, however, one to which I have been obliged to devote some attention, 

 since a certain knowledge of the faunas of the respective groups was abso- 

 lutely essential to enable me to map the lines of separation, when, as was 

 frequently the case, stratigraphical evidence failed; and as a long period will 

 probably elapse before the description and publication of the entire fossil 

 series can be accomplished, a few words here on so important a subject 

 will not be out of place. 

 The fauna of the Ootatoor Group has been hitherto less known than 

 TT.„ . X- 1 that of any of the associated formations. iUessrs, 



Hitherto comparatively <^ 



unknown. Kaye and Cunliffe's original collection, described 



by Professor Forbes, contained no specimens from this group ; and as I 



* Except in tlic case of the Belcniuites, Nautili, and some Anmionitcs. 



