118 



The paper contains many valuable remarks on the habits and 

 distribution of species. The whole number of species enumerated 

 is 228, belonging to 81 genera — besides 3 fossil species, Nucula 

 Portlandica, N. antiqua and Bulla occulta, he gives 37 species not 

 yet found in Massachusetts or its waters, most of which had been 

 recently discovered and described by himself. Among them he 

 enumerates Solen Caribceus, Terebra dislocata and Area — species 

 of a much more southern habitat. Dr. M. thinks their presence on 

 the coast of Maine is accounted for by the fact that a southerly 

 current sets upon it during a part of the year. Dr. M. considers 

 the shell formerly described by him as Pecten tenuistriatus, the 

 young of P. Magellanicus, and Chiton fulminatus Couth, as iden- 

 tical with C. lavigatus Fleming. 



Dr. Gould also read extracts from a paper lately received 

 by him from Rev. Francis Mason, Missionary in British 

 Burmah and a Corresponding Member of the Society. 



It gave an account of the geographical, botanical and geolog- 

 ical features of Tavoy and Mergui, accompanied by a map, and 

 specimens of the rocks ; the principal of which are Granite, Sand- 

 stone, Clay Porphyry, Clay Slate, Chlorite Slate, Mica Slate, Lime- 

 stone with veins of Trap, and Lignite. He mentions isolated 

 masses of mural, mountain limestone, in one instance several hun- 

 dred feet high, abounding with cylindrical pits a few feet in diame- 

 ter, of unknown depth ; which Mr. M. thinks may resemble the 

 wells described by Mr. Murchison in the limestone of Wales. A 

 series of Hot Springs runs parallel with the slate strata, and they 

 are always found near the junction of the slate with the granite, or 

 in the granite itself. The hottest of the springs mentioned by Mr. 

 M. is at Pai, among granite rocks, through which water bubbles up, 

 at a temperature of 198° Fahr. The water of all of them is free 

 from sulphurous smell, and no mineral has yet been detected in 

 solution. One, however, at the junction of slate with a trap dyke, 

 is strongly impregnated with sulphuretted Hydrogen. 



Sometimes the sides of the hills and the ravines between them 

 are covered with diluvial and alluvial pebbles, among which Tin is 

 found, but never at a greater depth than 8 or 10 feet below the 

 surface. The principal deposit of Tin is evidently in the rocks of 

 the neighboring mountains 



