762 Geological Notes on the Northern Conkan. [Dec. 



speculations, not even giving a name" to that which is found, — hy 

 carefully noting the site of specimens collected, according to the 

 directions published by the Geological Society of London, — by for- 

 warding collections to those persons who are best capable of com- 

 paring and identifying fossil remains, — materials will gradually be 

 formed for a geological map of India, as well as for the develop- 

 ment of sound doctrine regarding the mode and date of deposits. 

 Let the traveller who goes northward over the plateau of the Dekhan, 

 or who follows up the coast of the Conkan, conclude with Dr. Benza 

 that the primary, the trap and the laterite rocks — nay, even the alluvial 

 covering these, are antecedent to the existence of animal life on our 

 planet. But, on finding in parts of the Southern Conkan, and espe- 

 cially in the island of Bombay, horizontal strata of sandstone contain- 

 ing shells, it would be well to look with more suspicion to the 

 northward, and to be prepared to doubt the non-fossiliferous charac- 

 ter of the rocks. The shell-stone of Bombay will, I hope, be investi- 

 gated agreeably to modern rules, and materials furnished to those 

 who are capable of deciding whether any, or what proportion of the 

 shells belong to extinct species. It is easy to name this stone " coral 

 rag," and it would cost no labour to speculate upon its being simply 

 a deposit actually going on at the bottom of the Bombay harbour ; a 

 deposit here and there brought to light in consequence of portions of 

 the present island having been gained from the sea since the place 

 became a settlement. This question can only be determined in one 

 mode ; — by the examination and comparison of a few hundreds of 

 species of shells. Decide then whether all are existing, or part 

 extinct. Leaving this important matter for the investigation of some 

 persons at the Presidency, I proceed to copy a few notes collected in 

 a tour through the Northern Conkan, part of Guzerat, and Kattywdr. 

 The most remarkable geological feature in the Northern Conkan 

 between Bassein and Surat, is the extensive degradation and partial 

 reproduction of land at different periods. Occasionally, denuded- 

 strata are met with, the date of which can alone be determined by 

 the nature of their organic remains. The first place at which I remark- 

 ed strata of sandstone similar to those of Bombay, was at Mahim, 

 (Northern Conkan.) There is a low cliff of from ten to twelve feet in 

 height, composed of horizontal strata from one to three or four inches 

 in thickness. On leaving the town of Mahim the road passes over a 

 tract of some extent formed of these shell strata, which after some 

 intermediate alluvial, which conceals the nature of the subjacent for- 

 mation, reappear at the coast under the fort and public bungalow of 

 Seergaum. 



