PELECYPODA. 55 



Pisidium walkeri var. mainensc Sterki, Nautilus, 1898, vol. 12, p. 

 79. " Caribou, Aroostook Co., Maine." 



Me. — Hacket's Mill Brook; Woodland; Barren Brook, Caribou; 

 Westmanland. 



Pisidum fallax Sterki. 



Sterki, Nautilus, 1896, vol. 10, p. 20. " Ohio." 



Me. — Aroostook River. 

 Mass. — Groton. 



*Pisidiuin fallax boreale Sterki. 



Pisidium fallax var. sep[t]entrionale Sterki, Nautilus, 1898, vol. 

 12, p. 78 {no7i Prime, 1895). [Minnesota and Aroostook Co., 

 Maine.] 



Pisidium fallax var. boreale Sterki, Nautilus, 1899, vol. 13, p. 12. 



Pisidium fallax var. errans Sterki, Nautilus, 1905, vol. 19, p. 84. 



Me. — Little Madawaska River at New Sweden, and Aroostook 

 River at Caribou (Nylander). 



*Pisidiuin pauperculum Sterki. 



Sterki, Nautilus, 1896, vol. 10, p. 64. [Massachusetts to 

 Minnesota.] 



Me. — Caribou; Little Madawaska River, New Sweden; West- 

 manland. 



Mass. — Winchester; Newton Upper Falls; Groton. 



*Pisidiuin pauperculum nylanderi Sterki. 



Pisidium pauperculum var. nyhmderi Sterki, Nautilus, 1898, 

 vol. 11, p. 125. " Maine and New Jersey." 



Me. — Caribou Stream; Portage, Long, and Square Lakes, Aroos- 

 took Co. 



