44 THE NAUTILUS. 



from magnifica by being smootli or nearly so, some being nearly as 

 smooth as viviparus. They are found under rocks in the swift 

 current of the stream. Both forms, magnijica and angulata, vary 

 greatly in color from a light horn to a dark purple. 



Cumpehma ponderosuin Say. Tennessee River, Decatur ; Coosa 

 River, Wilsonville ; Fort William Shoals and Wetumpka. 



C. coarctatum Lea. Black Warrior River, Warrior ; Tallapoosa 

 River, Tallassee. 



C decisuin Say. Tennessee River, Decatur. 



0. nolani Tryon. Coosa River, Wetumpka. 



Lioplax cychstomatiformis Lea. Black Warrior River, Warrior; 

 Coosa River, Fort William Shoals and Wetumpka. 



FAMILY VALVATIU^. 



Falvata bicarmata Lea. Coosa River near the railroad bridge,^ 

 Farmer, Ala., but three specimens found. 



FAMILY AMNICOLID^t;. 



Somatogyrus aureus Tryon. Coosa River, Fort William Siioals, 

 rare. 



S. constrictus Walker. Coosa River, AYetumpkaand Wilsonville, 

 very few; nearly always found on the underside of the rocks associ- 

 ated with S. coosaensis and S. hinkleyi, very seldom more than one on 

 the same rock. The light color, eroded spire and deep suture made 

 them easily noticed among other species. 



S. coosaensis Walker. Wetumpka, Fort William Shoals; common. 

 On rocks in swift water; sometimes 25 to 30 were seen together. 



S. crassus Walker. Wetumpka and Fort William Shoals ; not 

 plentiful. 



S. hinkleyi Walker. At all localities in the Coosa River. One 

 specimen supposed to be from the Tallapoosa River above Tallassee, 

 was probably mixed with S. pilshryanus by accident. 



S. nanus Walker. Very plentiful at Fort William Shoals. They 

 literally covered the rock-bed of the stream in favorable situations, 

 showing up very plainly through the clear water, but owing to the 

 swift current it was difficult and tedious collecting them. 



S. obtusus Walker. Coosa River, Farmer, above the railroad 

 bridge, found among the drift in a stagnant pool, made by the low 

 stase of water. 



