THE NAUTILUS. 43 



stream running from the spring, they were in algse and on the muddy 

 bottom. 



Somatogyrus subglobosa Say. Tallahatchie and Yalabusha rivers. 



Somatogyrus georgianus Walker. Tennessee river, Florence, Ala. 



Somatogyrus substriatus Walker. Tombigbee and Tennessee 

 rivers. The most plentiful species of the genus in these two streams. 



Somatogyrus humerosus Walker. Tennessee river, Florence, Ala. 



Somatogyrus quadratus Walker. Tennessee river and Shoal crock. 



Somatogyrus strengi Pilsbry and Walker. Tennessee river and 

 Shoal creek. 



Somatogyrus biangutatus Walker. Tennessee river, Florence, 

 Ala. 



Somatogyrus excavatus Walker. Shoal creek, Florence, Ala. 



Somatogyrus tennesseensis Walker. Shoal creek. 



Somatogyrus purnilus Conrad. Tennessee river, Florence, Ala. 



Pyrgulopsis mississippiensis Pilsbry. Shoal creek. This little 

 species was numerous a short distance above the canal aqueduct, 

 where sediment had collected on the rock bottom, a few were found 

 on algae. They were only found in mid-stream. 



Pomatiopsis lapidaria Say. Found on leaves after a shower, in a 

 moist situation, always shaded by timber and scrub palmetto. Boligee, 

 Ala. 



Pomatiopsis hinkleyi Pilsbry. This species was very numerous in 

 the same places where the types were found in 1894. It was also 

 found across the river high up on the river bluff, on and in damp 

 moss but not in a wet situation like the others. See vol. X, p. 37 

 of the NAUTILUS. 



Family CORBICULID^E. 



Calyculina transversa Say. Yalabusha, Black and Tombigbee 

 rivers. 



Calyculina occidentalis Prime. Creek, Boligee, Ala. 



Sphaerium striatinum Lam. Big Black river, Durant, Miss., 

 Boligee, Alabama, one specimen at last place. 



Sphaerium stamineum Conrad. Young specimens, Grenada, and 

 one mature at Durant, Miss. 



Pisidium virginicum Gmel. Durant, Miss. 



Pisidium compression Prime. Tuscumbia spring; Black War- 

 rior, Tuscaloosa, and Shoal creek, Florence, Ala. 



