PELECYPODA. 47 



Vt. — Chimney Point, Lake Champlain ; Lake Memphremagog. 

 Mass. — Pontoosuc Lake, Berkshire Co. 



*Sphaeriuni emarginatum (Prime). 



Prime, Smithson. Misc. Coll., 1865, vol. 7, art. 5, p. 43, fig. 38. 

 Cyclas cmarginaia Prime, Proc. Boston Soc. Nat. Hist., 1852,. 

 vol. 4, p. 156. " Lake Superiok." 



Me.— Eagle Lake. 



*Sphaeriuin rhomboidum (Say). 



Cyclas rhomboida Say, Journ. Acad. Nat. Sei. Phila., 1822, ser. 1, 

 vol. 2, p. 380. " Lake Champlain." 



Cyclas elegans C. B. Adams, Boston Journ. Nat. Hist., 1840, 

 vol. 3, p. 330, pi. 3, fig. 11. 



Sphaerium rhomboideum Prime, Smithson. Misc. Coll., 1865, 

 vol. 7, art. 5, p. 39, fig. 31. Gould, Inv. Mass., 1870, p. 104, fig. 409. 



Me. — Gelot Lake, New Sweden; Little Madawaska River. 

 Vt. — Chimney Point, Lake Champlain. 



Mass. — Cambridge; Readville; Newton Upper Falls; Housa- 

 tonic River, Lenox. 

 R. L— Pawtucket. 

 Conn. — Housatonic River. 



Sphaerium fabale (Prime). 



Cyclas fabalis Prime, Proc. Boston Soc. Nat. Hist., 1852, vol. 4, 

 p. 159. " Lake Superior." 



Sphaerium fabalis Prime, Smithson. Misc. Coll., 1865, vol. 7, 

 art. 5, p. 40, fig. 33. 



Vt. 



Conn. 



*Sphaerium occidentale (Prime). 



Prime, Smithson. Misc. Coll., 1865, vol. 7, art. 5, p. 41, fig. 34. 

 Gould, Inv. Mass., 1870, p. 108, fig. 414. 



