4 
The specimens belong to a compact, rather narrowly umbilicated race 
of ptycophora, not as large as most Idaho and Washington shells, but notably 
larger than such Montana specimens as the writer has seen. They are 
evidently the ones which have already been reported by Whiteaves (1906, 
p. 119). 
Oreohelix cooperi limitaris (Dawson 1875) 
Plate I, figures 1-5 
1875. Helix limitaris Dawson, — Rep. Geol. Brit. N. Am. Boundary Comm., 
p, 347. 
1885. Patula strigosa var., immature, Binney, — -Man. Am. Landsh., p. 261 
(reprints Dawson’s description). 
1895. Patula strigosa var. Taylor, — Ottawa Nat., vol. 9, p. 173 
(brief note). 
1898. Pyramidula solitaria limitaris Pilsbry, — Nautilus, vol. 11, p. 140 
(merely catalogued). 
1905. Pyramidula solitaria var. limitaris Dali, — Land and Freshwater 
Moll. Alaska, p. 49. 
1916. Oreohelix strigosa limitaris Pilsbry,— proc. Acad. Nat. Sci. Phila., 
1916, p. 353 (merely catalogued). 
1919. Oreohelix cooperi limitaris Berry, — Proc. Acad. Nat. Sci. Phila.. 
1919, pp. 196, 201. 
Material Examined 
V 
No. of 
* j. 
Geol. Surv. 
spec. 
Locality 
Collector 
Date 
Cat. No. 
7 
Water ton lake, Alberta 
J. B. Tyrrell 
Aug. 25, 1883.... 
2881 
3 
ft it 
“ 25, 1883.... 
3144 
Description. The shell is of only moderate size, fairly elevated, with 
an obtuse apex. The spiral sculpture is obsolete below, and on the upper 
surface of the whorls is only moderately developed, being much broken 
and interrupted by the very coarse and irregular lines of growth. The 
periphery is obtusely angular in front, becoming rounded or but faintly 
subangular on the forward part of the last whorl. The umbilicus is deep 
and narrow, contained in the diameter seven to eight times, its circular 
outline but little interfered with by the slightly reflexed inner lip. 
The colour of the somewhat dehiscent periostracum is a deep rusty 
brown, irregularly clouded with brownish cream and slaty tones, and with 
two conspicuous, encircling, seal brown bands, one on the shoulder, the 
other just below the periphery, with sometimes a lighter and less distinct 
band interpolated between them, or one or more similar secondary bands on 
the basal part of the shell, and there is sometimes one just below the suture. 
The embryonic shell seems essentially similar to that of 0. c. apiarium 
as described (cf. Berry, 1919, p. 200, f. 1), but is smaller, the spiral sculpture 
is weaker, and the axial riblets stronger and more regular. 
