THE NATURAL HISTORY SURVEY. 23 
Length, 2.00; diameter, 1.15; aperture length, 0.85 mill. (11996.) 
Ammal: Of the usual form; color grayish white under- 
neath and blackish above and on eye-peduncles. The foot is 
quite long and rather wide; eye-peduncles rather long and 
somewhat tapering; tentacles rather long, blunt, cylindrical. 
Faw: Similar to thatof V. milum, slightly arcuate, width 
uniform, ends broadly rounded; concave margin notched and 
anterior surface striated longitudinally. 
Radula formula: 3$,+4+4+4+,5, (10—1—10); central 
tooth long and narrow, the tricuspid reflection very small; 
lateral teeth very wide, reinforced at the lower outer corner bya 
very small appendage to the base of attachment; marginals 
as in the other species. There are over 60 rows of teeth. 
Genitaha: Unknown. 
Distribution: “Ontarioand Quebec, Canada, to Minnesota, 
south to Georgia. and Texas; Lincoln Co., Nevada; Laggau, 
B. C.” (Pilsbry.) Manitoba. (Hanham.) 
Geological distribution: Pleistocene. 
Habitat: Found about dead leaves under sticks, stones 
and rubbish, and about the foot of trees in low, moist locali- 
ties. 
Remarks: This species is distinguished from all our Pupe 
by the small size and number of the teeth in the aperture, and 
also by the teeth being simple, especially the parietal tooth, 
which is small and narrow. It seems to be quite common and 
loves to congregate under leaves in little colonies. It is found 
in both the northern and western regions. One of the best 
times to collect this species is after a rain, when they will be 
found crawling over fallen trees, leaves and old débris. 
95. Bifidaria curvidens Gould. Text figure 69. 
Pupa curvidens GOULD, Journ. Phil. Acad., Vol. II, p. 476, 1822. 
Pupa curvidens floridana DALL, Proc. U.S. Nat. Mus., p. 251, pl. xvii, 
fig. 11, 1885. (Variety.) 
Pupa curvidens gracilis STERKI, L. and F. W. Moll., New Phil., Ohio, 
1894, (Variety.) 
Shell: In general form like that of pentodon but smaller; 
aperture more rounded than in fenfodon and six-dentate, as 
follows: a single large, curved tooth on the parietal wall, which 
descends for a considerable distance into the aperture; a large 
columellar tooth, conical, placed about the middle of the col- 
umella; a third very small, conical tubercle placed at the left- 
hand turn of the peristome; a fourth, small, conical tubercle 
