100 CONCHOLOGIA CESTRICA. 
S. rosaceum, PRIME. 
Cyclas rosaceum, Prime, Bost. Proc., IV., 1851. 
S. rosaceum, — [Prime.] 
Fig. 201, 

Shell, small, round-oval, fragile, transparent, sub- 
equilateral ; margins generally rounded; beaks calycu- 
late, approximate, inclined forward; valves very slight, 
a little convex, fine striate; epidermis reddish-brown, 
shining; teeth very slight, laterals elongated. H. 4%, 
W. 6, T. 3%, mill. 
Station, Pickering Creek, and Schuylkill River, Ches- 
ter County ; rare. 
S. partumeium, Say. 
Cyclas partumeium, Say, Acad. Nat. Science, Jour. 
ITs, 1822: 
S. partumeium, — [Prime.] 

Shell, round-oval, thin, pellucid, nearly equilateral, 
anterior margin slightly distended; posterior rather 
abrupt; beaks central, calyculate, approximate; striz 
scarcely visible; glossy, greenish horn color; valves 
moderately convex; hinge margin nearly straight; 
cardinal teeth strong; laterals very much elongated. 
Hye, Wea, T.. 8 sonillt 
Station, stagnant ponds on White Clay and Pickering 
Creeks, Chester County ; abundant. 
