392 Geological Society. 



about one hundred species from the Paris basin were at once recog- 

 nised by the author as familiar objects, from his acquaintance with 

 those from Kossiaand Cherraponji : these consisted of about an equal 

 number of species, and on being submitted to systematic comparison 

 about twenty species were found to be identical in the two collections. 



On crossing this deposit, the rock composing the superficial strata 

 of sandstone forming the precipices of the second part of the ascent, 

 was found to contain the impressions of shells and other organic re- 

 mains, which the author believes to be ramose Alcyonia ; these 

 continued to appear all the way up to Cherraponji, where they oc- 

 curred in the greatest numbers. 



On this sandstonereposesadepositof compact !imestone,from which 

 twenty-seven species of shells were extracted, as species of Trochites, 

 Cerithia, and of Modiola of Lamarck, with Piliolus plicatus of Sow- 

 erbv. On this formation reposes a bed of coal to the depth of above 

 twenty or thirty feet, in which was found an exogenous plant. On 

 descending towards the plain from a point five or six miles west of 

 Cherraponji, and one or two miles below the village of Mumloo, an 

 elongation of the same fossil beds and sea beach was met with at 

 about the same elevation. The shells and characteristic remains, with 

 six species of Medusae, were found imbedded in a red sandstone, or 

 rather indurated sand, immediately beneath the soil. 



On crossing the mountains towards the centre of the group, the 

 sandstone, on which the limestone and coal rest at Cherraponji, was 

 found for fifteen or eighteen miles, forming in horizontal strata lofty 

 undulating lands, with little variation except in ravines and the banks 

 of streams. Beyond the above distance the strata displayed marks 

 of confusion, and in the first deep river valley, a mass of greenstone 

 was found with the adjoining sandstone tilted up in highly inclined 

 tabular masses, formed of quartzose pebbles imbedded in felspar. 

 This form continued to the second deep valley, where the greenstone 

 was again met with, and the adjoining sandstone compact, glossy, 

 and columnar. 



Leaving this (the Boga Pany) and ascending the opposite ac- 

 clivity, all traces of the earthy sandstone are lost, and the centre of 

 the mountains from Mufling to the highest ridges is composed of 

 syenite. Granular quartz, slaty and in vertical strata, is found in con- 

 tact with this, and interposed between it and the common sandstones ; 

 displaying progressive changes from one to the other. The northern 

 side of the mountains from Muflong into Assam is composed of gra- 

 nular foliated felspar, penetrated by quartzose veins, and more irre- 

 gularly with beds of mica. Extensive beds of syenite and central 

 nuclei of granite are found as far as the Valley of Lower Assam, which 

 here is about thirty miles broad, and bounded on the north by the 

 Bustan Mountains. Groups of rocky hills extend from the Kossia 

 and Garrow Mountains across the valley, threatening as it were to in- 

 terrupt the waters of the Bramaputra and convert the interior of the 

 valley into a lake. These called the Meeker Hills, are composed of 

 insulated rocky protrusions of metamorphosed gneiss, in some in- 

 stances syenitic, in others as a sandstone whose base is earthy felspar 



