188 



fish, gives a detailed description of the old red sandstone, the schistose 

 formation, and the trap rocks of the district. He gives a detailed ac- 

 count, also, of the faults, and shows by sections, that those between 

 Findon and Gamrie, and near Gamrie church, are older than the 

 lias, because they are overlaid by that formation, without attect- 

 ing it. 



April 29. — John Wiggins, Esq , of Tavistock Place ; George 

 Vaughan, Esq., of Cumberland Terrace, Regent's Park ; Lord Abin- 

 ger. Lord Chief Baron, of Spring Gardens ; and Christopher Puller, 

 Esq., Barrister at Law, Park Street ; were elected Fellows of this 

 Society. 



A paper was first read, entitled " Remarks to illustrate Geological 

 Specimens from the West Coast of Africa," by Captain Belcher, R.N., 

 F.G.S., &c. 



The points whence the speciniens were obtained are the Lsles de 

 Los, in lat. 9° 27' north ; the reef of Young Gonsalez j and Cape 

 Blanco, lat. 20° 47' north. 



The Isles de Los are stated to be composed principally of porphy- 

 ritic hornstone; but at the water's edge that rock is said to be inter- 

 sected by a granitic compound of quartz, felspar, and hornblende. 

 Tumbo Point, situated on the main land, opposite the Isles de Los, 

 consists of the same compound, as well as the coast for several miles 

 to the northward. When in mass this rock is said to affect consider- 

 ably the magnetic needle. 



From the mouth of the Sangareeah or Debreekah nearly to Cape 

 Verga, in lat. 10° 11', the coast consists of sand banks j but at Cape 

 Verga the granitic compound reappears. Off this Cape is a reef, 

 composed of masses of hard, calcareous sandstone and granular lime- 

 stone. The banks or shoals in the vicinity are frequently composed 

 of a jaspery gravel, and indurated ferruginous sand, apparently de- 

 rived from the reef oft" Young Gonsalez. The reef at the entrance of 

 the river Cappacches, and the whole of the coast to Rio Nunez, 

 are composed principally of a ferruginous sandstone, passing into a 

 breccia. In the Rio Nunez, basalt is stated to occur at the first falls 

 above Debucko ; and at " the barrier", about thirty-five miles from 

 the mouth of the river, the strata are said to be much disturbed, and 

 the sandstone to assume a prismatic structure. For five miles from 

 this point the banks were apparently composed of reddish and yel- 

 lowish clay. At " Five-miles' Bend" is a precipitous bank, stated to 

 consist of slate, spotted in some places with greyish steatitic matter j 

 and hence to one mile above Cassassez, no rock occurs, but at the 

 latter place the sides of the river and its bed are said to be composed 

 wholly of basalt, which is generally columnar. The peninsula of Cape 

 Blanco is formed of calcareous sandstone, in which shells occasionally 

 occur J and the surface of the clift", seventy feet above the level of 

 the sea, is stated to be covered with immense quantities of shells, 

 agreeing with those found in the bay. 



On some parts of the coast are ledges composed of strata of various 

 colours, dipping at a high angle towards the south, and often worn 

 ill forms resembling that of a mushroom. 



