PELECYPODA. 57 



*Pisidiuin politum Sterki. 



Sterki, Nautilus, 1895, vol. 9, p. 75. [Ohio, Penna., Mich., 

 III., and Minn.] 



Me. — Portage and Cross Lakes, Aroostook Co. (Nylander). 



*Pisidiuin punctatum Sterki. 



Sterki, Nautilus, 1895, vol. 8, p. 99, pi. 11, figs. 7-12. [streams 

 OF Portage Co., Ohio.] 



Me. — Portage Lake, Little Madawaska (Nylander). 

 Mass. — Wareham. 



Pisidium punctatum simplex Sterki. 



Sterki, Nautilus, 1905, vol. 19, p. 84. [Illinois; Michigan; 

 Wisconsin.] 



Me. — Caribou Stream, Woodland ; Georges River, North 

 Warren. 



Pisidium regulare Prime. 



Prime, Boston Joum. Nat. Hist., 1852, vol. 6, p. 363, pi. 12, figs. 

 11-13. " Miami Canal, near Cincinnati, Ohio." 



Mass. — Concord. 



*Pisidium trapezoideum Sterki. 



Sterki, Nautilus, 1896, vol. 9, p. 124. [Canada, Pennsyl- 

 vania, New Jersey (non Michigan, Minnesota and Texas, 

 Sterki).] 



Mass. — Cambridge (Roper Collection). 



*Pisidium affine Sterki. 



Sterki, Nautilus, 1901, vol. 15, p. 66. [Great Lakes Region, 

 New York to Minnesota.] 



