180 GEOLOGY. 



forms, and amply suffice to determine the series to which 

 these limestones belong. The fauna has a general resem- 

 blance to that of the middle Jurassics, but the evidence 

 is scarcely sufficient to justify any decided conclusions in 

 matters of detaU. 



The occurrence of trap beds interstratified with the 

 limestones is very interesting, because it indicates a com- 

 mencement, in the oolitic period, of the great series of 

 volcanic effusions, the remains of which stUl cap so many 

 of the Abyssinian mountains. It also shows that the 

 earliest lava-flows must in all probability have been 

 submarine, like the limestones with which they are 

 intercalated. It is worthy of note that the earliest great 

 outburst of traps of known age in India is also Jurassic. 



