THE NATURAL HISTORY SURVEY. 231 



Geological distribution: Pleistocene; Loess. 



Habitat: Found rather sparingly in the crevices of rot- 

 ting logs, under sticks, stones, etc., in damp places. 



Remarks: Corticaria is distinguished by its obtuse apex 

 and peculiarly armed aperture. The latter is very variable, 

 being either simple or with one or two small conical teeth. 

 The shell is peculiarly long and cylindrical, resembling some- 

 what Cochlicopa lubrica in general form. It is widely distrib- 

 uted. 



SECTION BIFIDARIA Pilsbry (Sensu stricto) 1900. 



1893.) 



"Shell cylindric to turriculate; lamellae typical." (Sterki.) 



90. Bifidaria procera Gould, pi. xxx, fig. 11. 



Pupa procera GOULD, Bost. Journ. Nat. Hist., Vol. Ill, p. 401, pi. iii, 



fig. 12, 1840. 



Pupa carniata GOULD, Olim, an abnormal shell. 

 Pupa gibbosa SAY, Kiister, and P. minuta SAY Pfr. (non Say). 

 Pupa rupicola SAY, Binney, Man. Amer. Land Sh., p. 328, fig. 354 (non 



Say i. 

 Pupa pellucida PFR., Strebel, Beitr. Mex., Theil IV, p. 91, pi. iv, fig. 12; 



pi. xv, fig. 10. 



Pupa hordeacea GABB, Binney, Man. Amer. Land Sh., p. 173, fig. 165. 

 Bifidaria procera cristata P. & V., Proc. Phil. Acad., p. 595, pi. xxii, 



figs. 4, 5, 1900. (Variety.) 



Shell: Cylindrical, long, shining; surface covered with 

 well-marked, oblique lines of growth, the apex smooth; color 

 brownish or chestnut-horn; whorls six, convex, the last three 

 about equal in size and the first three rapidly diminishing to 

 the nucleus, making an obtuse apex; sutures deeply impressed; 

 aperture ovate or semicircular, higher than wide; there are 

 generally five teeth placed as follows: one on the parietal 

 wall, large and somewhat compressed, long and bifid at the 

 end; one on the columella, near the upper third, short, coni- 

 cal; a third on the upper third of the outer lip, thick, conical, 

 short; a fourth on the base of the peristome, long, sharp; and 

 a fifth placed behind the columella tooth, large and massive; 

 peristome rather widely reflected, thickened, bluish-white; ter- 

 minations approaching and joined by a callus; umbilicus small, 

 open (Fig. 63). 



Length, 2.50; diameter, 1.00; aperture length, 0.50 mill. (12321.) 



Animal: Resembling that of corticaria. 



