THE NAUTILUS. 103 
Bulimulus lamellifer n. sp. 
General form of A. spirifer ; waxen white or light brownish; the 
surface more or less granulose, as inexamples of B. spirifer. Whorls 
about 63. Aperture over half the altitude usually, but sometimes 
less than half; the lip-ends conspicuously approaching, joined by a 
short callus; peristome broadly expanded and reflexed, much as in 
spirifer. Columella showing from the aperture a sharp, oblique lam- 
ina; this lamina becoming very high internally, projecting in a 
square or bisinuate plate. The type measures, alt. 32, diam. 15 
mm.; but they are very variable in size, the smallest seen being 
233 mm. long. The square or emarginate internal plate differs con- 
spicuously from the corkscrew twisted fold of B. spirifer, and is ap- 
parently a constant character. Seventeen specimens examined. 
Lower California (W. M. Gabb). 
These forms are evidently different from B. spirifer Gabb, B. 
bryanti Cooper and B. veseyanus Dall, the species of this group de- 
scribed by American naturalists. A careful comparison with the 
descriptions of B. lapidivagus, dentifer, subspirifer and dismenicus of 
Mabille, causes me to consider these also as specifically distinct from 
the forms described above. Illustrations will appear in the next 
number of the Manual of Conchology, in which the other North 
American Bulimuli will also be figured. 
NEW AMERICAN UNIONIDE. 
BY WM. A. MARSH, ALEDO, MERCER CO., ILL. 
Unio superiorensis n. sp. 
Shell smooth, obovate, slightly inflated, inequilateral, rounded 
before, oblique, obtusely angular behind, with or without rays, rays 
when present interrupted by lines of growth. Substance of shell 
thick, beaks small, with a few rather coarse undulations; umbonial 
slope flattened, ligament long, dark brown; epidermis dark olive; 
growth lines very close, quite prominent, cardinal teeth large and 
solid, compressed and nearly smooth, double in left valve and widely 
separated ; lateral teeth long, thick and nearly straight, anterior 
cicatrices deep and rounded, posterior cicatrices confluent and well 
impressed. Cavity of shell deep; cavity of beaks deep and rounded ; 
nacre white, sometimes shining. 
Habitat: Michipicoton River, upper shore of Lake Superior, 
Canada. 
