68 



of Pisidium, with a description by Mr. Temple Prime, un- 

 der the name of P. ventricosum. 



Pisidium ventricosum. P. testa minuta, globosa, tumida, 

 postice brevi et subtruncata, alba, nitida, tenui, striis concentri- 

 cis instructa, natibus prominentibus, marginibus abruplis. Long. 

 .11 ; lat. .095; diam. .085. Hab. Massachusetts. 



This shell somewhat resembles P. duhium^ but is much more 

 convex ; its beaks are considerably more elevated. 



It was found in a small stream running out of Fresh Pond, 

 Cambridge, in company with P. dubium and Cyclas truncata of 

 Linsley. 



Mr. Wells exhibited specimens of soil from the alluvial 

 lands of Ohio. He stated that he had recently been exa- 

 mining the soils of the prairies and bottom lands of that 

 State, and they were characterized by their extreme fineness. 

 In one specimen all but six and one tenth per cent, passed 

 through a sieve, the openings in which were only one 

 sixtieth of an inch in diameter. In another all but one and 

 fltre tenths per cent. For forty-five years such soil had pro- 

 duced eighty bushels of corn to the acre. He thought that 

 this fertility was due in a considerable degree to the fine 

 division of the soil, which would admit of a very free absorp- 

 tion of ammonia. 



Dr. Gould presented, in the name of Mr. Calvin Brown, 

 a donation of Fossils from Boulton Hill, near Sackett's Har- 

 bor, at a depth of from one foot to a foot and a half below 

 the surface. 



Dr. Cabot announced a donation of four birds from 

 Florida, in the name of Mr. F. C. Browne ; an Owl, which 

 flew on board a ship five hundred miles west of the West- 

 ern Islands, from Mr. Sprague ; and also the addition to the 

 collection of eleven birds received from Moses Kimball, Esq. 

 in exchange. The thanks of the Society were voted for 

 the donations. 



