PELECYPODA. 47 



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

 Mass. — Pontoosuc Lake, Berkshire Co. 



*Sphaerium emarginatum (Prime). 



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

 CycJas cviarginata Prime, Proc. Boston Soe. Nat. Hist., 1852,. 

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



Me. — Eagle Lake. 



*Sphaerium rhomboidum (Say). 



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

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



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

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



Sphaerium rhoviboideum 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. — Housa tonic 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. 



*Sphaeriuin occidentale (Prime). 



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

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



