ne LS 2S ae eta ee 
340 THE CHICAGO ACADEMY OF SCIENCES. 
termediate tooth with the body perforated, and the peduncle 
more than twice as long as the body; cusp 7-denticulated, the 
third denticle (counting from within) being twice as broad as 
the others. Inner lateral tooth with fourteen denticles at the 
summit. Outer lateral tooth also with fourteen denticles.” 
(Stimpson.)* 
Distribution: Central parts of North America. ; 
139. Somatogyrus subglobosus Say. Text figure 123. at 
Paludina subglobosa Savy, Journ, Phil. Acad., Vol. V, p. 25, 1825. 
Melania tsogona SAY, New Harm. Diss., Vol. II, p. 227, 1829. 
Paludina pallida LEA, Trans. Amer. Phil. Soc., Vol. VI, p. 22, pl. xxiii, : 
fig. 104, 1639. (Young.) ; 
Shell: Subglobose, solid, somewhat depressed; color yel- 
lowish-horn; surface shining; lines of growth fine, oblique, 
crowded; sutures much impressed; apex small, rounded, sub- 
Fic. 123. 
SOMATOGYRUS SUBGLOBOSUS Say. (Original.) 
hyaline; aperture orbicularly-ovate, somewhat produced at the mt 
lower part, whitish inside; spire short, depressed, rounded; 4 
whorls four, convex, the last swollen and all rapidly increasing; 
peristome simple, sharp, rather thick, the terminations joined 
by a light callus; base rounded, umbilicus small, narrowly open. 
Length, 7.00; width, 6.50; aper. length, 5.00; width, 4.75 mill. (coll. Jensen). 
Animal: Not examined. 
Radula formula: ~y+4+->2+4+12 (3-1-3); the cen- 
tral tooth almost square, the lower outer corners very much 
produced and the basal margin with a projection of asquarish 
shape; reflection seven-cuspid, the central cusp very long and 
sharp, reaching almost to the basal margin of central projec- 
tion, side cusps shorter; the lateral projections of the base of 
attachment are armed with three blunt, rounded denticles, of 
which the highest is about three times the length of the other - 
* Researches upon the Hydrobiinz, p. 21, 22. Stimpson remarks that the holes in the 
appendage of the intermediate tooth may be simply pits. I have not been able to either 
prove or disprove this statement. 
