445 



PROCEEDINGS OF NATURAL HISTORY SOCIETIES. 



GEOLOGICAL SOCIETY. 



June 14. — Rev. W. Whewell, Pres., in the chair. — A letter was read, 

 addressed to C. Lyell, Esq., from Dr. M'Clelland, who had been associating 

 with Mr. Griffith in the scientific expedition sent by the Indian government 

 under the direction of Dr. Wallich, to investigate the Natural History of the 

 country, and the circumstances under which the Tea plant is found wild in 

 Upper Assam. 



Some high land was seen between the channels of the Ganges and Burram- 

 pooter rivers, at the foot of the Kossiah Mountains, or that portion called 

 Garrow-hills ; rounded knolls are interspersed throughout the partially inundated 

 plain, and are composed of layers of sands, clays, gravels, and boulders, appearing 

 to be the remains of a talus of great extent, which had been partially swept 

 away by the great hill streams. The foot of the mountains is composed of a 

 rock in which Nummulites are found. On ascending the mountain acclivity over 

 limestone and sandstone rocks to Cherra Ponji (a station established at an eleva- 

 tion of above 5,000 feet, and reaching a height of 1,500 feet above the level of 

 the sea), the author discovered a stratum filled up with shells and marine exuviae 

 two feet thick, reposing upon sandstone and covered by soil, which resembled a 

 well-defined marine beach. Several hundred specimens were, and many thou- 

 sands might have been, obtained. The species were about 100 in number, and 

 when compared with about an equal number from the Paris basin, no less than 

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



The sandstone higher up the mountains than this deposit, contained impres- 

 sions of shells and other organic remains. On this sandstone reposes a deposit of 

 compact limestone, from which 37 species of shells were extracted, consisting of 

 species of Trockites, Ceritkioe, Mediolce, and of Pileolus plicatus, Sowerby. On 

 this formation reposes a bed of coal to the depth of about twenty or thirty feet, 

 in which remains of an exogenous plant were found. 



On crossing the mountain towards the centre of the group, the sandstone on 

 which the limestone and coal rest at Cherra Ponji was found for 15 or 18 miles, 

 forming in horizontal lofty undulating lands. Beyond this 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, 

 and compact and glassy in the neighbourhood of the greenstone. 



Beyond this (the Bogapani) all traces of sandstone disappear, and the centre 

 of the mountains from Mufiong to the highest ridges is composed of syenite. 



No. 14, Vol.11. 3n 



