462 Annals of the Carnegie Museum. 



87. Pisidium splendidulum corneolum var. nov. 



More oblique, well inflated, beaks more elevated and narrower; 

 often lighter in color to nearly colorless. 

 Habitat.- — Ohio, Indiana, Michigan. 



88. Pisidium splendidulum novangliae ^'ar. nov. 



Much smaller, about 2 mm. long, well inflated, beaks rather narrow. 

 Habitat. — Maine, Massachusetts. Common, often associated with 

 larger forms. 



89. Pisidium splendidulum miliastrum var. nov. 



Small, superior and inferior margins little curved to nearly straight; 

 well inflated; resembling small forms of P. milium. 

 Habitat. — Maine, Massachusetts. 



90. Pisidium lermondi Sterki. 



Pisidiu7n lermondi Sterki, Naiitibis, XXVI, 1913, p. 138. 



In shape markedly dift'erent from all other Pisidia, yet it may be 

 near P. splendididnm. 



91. Pisidium milium Held. 



Pisidium milium Held, I sis, 1836, p. 280; Ci-essin, Monogr. Cycladeen in Martini- 

 Chemnitz, 1879, p. 20, PL 2, figs. 4-7; PI. 5, figs. 16-17 (the figures show the 

 outlines tco angular); B. B. Woodward, British Pisidia, 1913, p. 70, figs. 



Habitat. — Palearctic and Nearctic Regions; Maine, New York, 

 Ontario, Michigan, Minnesota, Manitoba. 



92. Pisidium contortum Prime. 



Pisidium, contortum Prime, Ann. N. Y. Lye, VI, 1853, p. 65, PI. I, fig. 2; Mon. 

 Corb., 1865, p. 73. 



Described as fossil, but lately found also as recent. 



Habitat. — Maine, Ontario, Michigan. 



Fossil. — Massachusetts (Originals), Maine, Ontario, Michigan. 



93. Pisidium contortum (?) triangulate \ar. nov. 



Smaller, shorter, especially the anterior part; beaks narrower. 

 Fossil. — Maine, Michigan. 



94. Pisidium imbecille Sterki. 



Pisidium imbecille Sterki, Nautilus, XIV, 1900, p. 5. 



Habitat. — -Maine, Michigan, Montana (Pacific drainage). 



