432 Annals of the Carnegie Museum. 



2. Sphaerium sulcatum albescens var. no v. 



Straw-colored to whitish in young and half-grown specimens; 

 darker, somewhat grayish-corneous in old specimens. Superior and 

 inferior margins little curved; beaks rather narrow, and somewhat 

 anterior; striae fine and crowded; hinge slight. A well-marked vari- 

 ety, somewhat variable. 



Habitat. — Maine, Massachusetts, eastern New York. 



3. Sphaerium sulcatum insigne \ar. nov. 



Larger, some specimens attaining 23 mm. in length, more elongate, 

 well inflated; superior and inferior margins little curved; anterior and 

 posterior ends rounded; beaks somewhat anterior, rather narrow, and 

 slightly prominent; surface striae fine, crowded; straw-colored, light 

 corneous around the beaks; shell and hinge slight. 



Habitat. — Grand Rapids, Michigan. 



Specimens are found in the Cincinnati Museum obtained from Cope, 

 and ticketed "No. 5088." Some good specimens are also in the 

 American Museum of Natural History, possibly from the same place 

 (source and locality not indicated on label). This form is remarkable 

 for its size, shape, and color. 



4. Sphaerium sulcatum planatum var. nov. 



Smaller than common, or typical, sulcatum, more inequipartite, the 

 beaks being markedly anterior; less inflated, especially flattened over 

 the lower parts of the valves, more truncate anteriorly and posteriorly, 

 inferior margin less curved; beaks narrower and little elevated; sur- 

 face striae slighter; shell and hinge slighter. Extreme forms are so 

 very different as to appear distinct, but there are intermediates. 



Habitat. — Ohio, Indiana, Illinois, Michigan, Ontario. 



Fossil. — Ohio. 



5. Sphaerium crassum Sterki. 



Nautilus, XI\\ 1901, p. 140. 



Most examples are larger, more elongate, and more inecjuiiJartite 

 than the original types from Michigan. 



Habitat. — Northern New York, Quebec, Ontario, northern Michigan, 

 Minnesota. 



6. Sphaerium aureum (Prime). 



Cydas aurea Primk, Boston Proc, 1\', i8"5i, p. 150. 

 .SphcErium aureum Prime, Man. Cotb., 1865, p. 35. 



