336 THE CHICAGO ACADEMY OF SCIENCES. 
supporting only two denticles, and a bulge near the lower end; 
process on concave margin large; intermediate tooth of the 
usual shape, but the denticles longer and narrower than in 
limosa and the central denticle rounded and blunt, the others 
sharp; inner and outer lateral teeth denticulated as in Amosa 
(Fig. 121). The figure of this species in Binney’s ‘‘Land and 
Fresh Water Shells” (Fig. 162), taken from Troschel, must bean 
error, for it does not at all correspond with the specimens ex- 
amined by the writer, which are undoubted cincinnatiensts. 
The species is peculiar in having the cusps of the intermediate 
tooth long and sharp, and in the central cusp being wide and 
blunt. The figure in Binney’s is probably the radula of some 
Pomatiopsis, perhaps P. lapidaria.* 
Fie. 121. 
Radula of AMNICOLA CINCINNATIENSIS Lea. (Original.) C, central 
tooth; I, intermediate tooth. 
Distribution. New York to Utah, south to Texas. 
Geological distribution: Pleistocene. 
Habitat: Same as limosa. 
Remarks: This is the largest species of Ammicola found 
in this region and attains a lengthof five or six mill. Its large 
size, swollen whorls, and elevated conic spire will at once dis- 
tinguish it from related species. It is rather common, espe- 
cially at Joliet, where it is the prevailing species. 
137- Amnicola emarginata Kiister, pl. xxvi, fig. 10. 
Paludina obtusa LEA, Proc. Amer. Phil. Soc., Vol. II, p. 34, 1841, non 
Troschel, 1837, 
Paludina emarginata KUSTER, Paludina, Conch. Cab., p. 50, pl. x, figs. 
3, 4, 1852. : 
*It should be noted here that the present figure is drawn to a larger scale than that of 
the radula of Amnicola limosa. The radula of A. cincinnatiensis is smaller and the den- 
ticulations are smaller, narrower and sharper than in A, dimosa. 
oe be 
