170 BULLETIN OF THE 
account of its very depressed form and the ovate form of the aperture, the heavy 
callus joining or “ yoking ” together the extremities of the peristome. 
The above is Hemphill’s description. 
The figure in the Third Supplement is drawn from an authentic specimen. 
Patula strigosa, Gourp, var. intersum, HEMPHILL. 
Shell umbilicated, sublenticular, depressed, thin, dark horn-color, more or less 
stained with darker chestnut. Whorls 54 or 6, somewhat flattened above, more 
convex beneath, obtusely carinated at the periphery, and bearing numerous coarse 
oblique rib-like strie, and two dark revolving bands; suture well impressed; um- 
bilicus large, pervious; aperture oblique, subangulated ; peristome simple, thick- 
ened, its terminations joined by a thick callus. Height of the largest specimen 4 
inch, breadth ¢ inch. Height of the smallest specimen $ inch, breadth 77 inch. 
Patula strigosa, var. intersum, HEMPHILL, The Nautilus, 1890, p. 135. 
Bluffs along the banks of Little Salmon River, Idaho. 
This shell inhabits stone piles at the foot of a steep bluff back some distance 
from the river. It seems to be quite rare, as I found but few specimens during 
the two or three days of my stay in its vicinity, and many of them were dead. I 
regard it as one of the most interesting shells found by me during the season, for 
it combines the depressed angulated or keeled forms of the Haydeni side of the 
series with the sculpturing of /dahoensis, two shells representing opposii 2 charac- 
ters in every respect. It thus becomes the companion of Wahsatchensis, a beautiful 
shell, combining the same characters, but much more developed, and connected 
with the large elevated forms. Var. intersum fills the opposite office, by uniting 
these characters with the small depressed forms. Taken as a whole, this series of 
shells, as now completed, seems to me to offer the best guide or key to the study 
of species that the student can have. Every known external character belonging 
to the genus Helix is so gradually modified and blended with opposite characters, 
that, if one had the moulding or making of the many and various intermediate 
forms, he could scarcely make the series more complete than Nature has done 
herself. 
The above is Hemphill’s description. 
Patula strigosa, Gourp, var. globulosa, CockrreEtt. 
Small, globose, dark above periphery, with two bands, transverse grooved striæ 
rather well marked. Diameter 114, alt. 84 mm. Black Lake Creek, Summit Co. 
The specimen seems immature, but is remarkable as being the only form I have 
seen in Colorado that is nearer to strigosa than Cooperi. It is doubtless allied to 
var. Gouldi, Hemphill. (Cockerell.) 
Patula strigosa, var. globulosa, CockERELL, The Nautilus, 1890, p. 102. 
The above is Cockerell’s description. 
The above varieties of Patula strigosa are transversely ribbed. The following 
are smooth or striate 
