THE NATURAL HISTORY SURVEY. 237 
‘its upper end turning in nearly a right angle toward the ap- 
erture, but not reaching the margin;” one on the base, small, 
conical; three on the outer lip, as follows: one just above the 
basal denticle, rather long, narrow, curved downwards; one in 
the middle of the outer lip, short, conical; and the third near 
the upper part of the lip, very small and conical; peristome 
reflected, the terminations joined by a very thin callus; um- 
bilicus small, open* (Fig. 67). 
Length, 1.75; diameter, 0.75; aperture length, 0.30 mill. (12322.) 
Animal: Not seen. 
Faw: Not examined. 
Radula: Not examined. 
Gentaha: Unknown. 
Distribution: Ohio to Manitoba, New Mexico, Kansas. 
(Sterki.) Put-in-Bay Island, Lake Erie. (Bryant Walker.) 
BIFIDARIA HOLZINGER! Sterki. (After Binney, Bull. Mus. Comp. 
Zool,, Vol. XIX, No. 4, p. 194.) 
Geological distribution: Pleistocene; Loess. 
Habitat: Similar to that of B. contracta. 
Remarks: This species is closely related to both armifera 
and contracta. Dr. Sterki says: “Our species ranges beside B. 
armifera and B. contracta Say, standing nearer the latter. Yet 
it is different from this species by the shape of the aperture, 
the wanting callous connecting the margins on the body whorl, 
by the longer crest behind the aperture, which in contracta dis- 
appears in about the middle of the (height of the) whorl, and 
by the wanting constriction, especially in the columellar wall, 
not to speak of the size and shape of the whole shell. The 
lamellz also show some marked differences, such as the pres- 
ence of a high basal, the shorter columella not reaching the 
*See Sterki, The Nautilus, l.c.,and Binney, Third Supplement, Bull. Mus. Comp. Zool., 
Harv. Coll., Vol. XIX, No. 4, p. 193, to which the writer is indebted for much assistance. 
