MUSEUM OF COMPARATIVE ZOOLOGY. 33 



This variety differs somewhat in the sculpturing. The wrinkles are usually 

 less developed than in the previously mentioned varieties, but on a few indi- 

 viduals are coarser. Those from Eastern Oregon are almost smooth. The 

 principal characteristic of the variety is its color, which is uniform chestnut, 

 excepting around the umbilicus. A few Like the one figured have a double 

 revolving white band. 



This closes the series of transversely ribbed varieties. 



B. SHELL SMOOTH OR STRIATE. 



In this section Mr. Hemphill suggests including the typical Mrigosa (see 

 PI. XXVL*), a large, flattened, widelj^ umbilicated, almost discoidal form, and 

 the typical Cooperi (Vol. IV. PI. LXXVII. Fig. 11), a small, elevated, globose, 

 narrowly umbilicated shell, as well as the innumerable varieties of size and 

 form and coloring which exist, some of which I have figured in Vol. IV. In 

 none of these variable forms do we find either transverse or revolving ribs. 



Some individuals are of a dirty white, but usually two revolving chestnut 

 bands are present : others, retaining the bands, are mottled with light or dark 

 horn-color, or more or less completely banded or uniformly colored with light 

 or dark chestnut. Within the peristome on some is a decided denticle, such as 

 I have already described above for other varieties of the group. (PI. II. Fig. 4.) 



One colony from Eastern Oregon is peculiar in form. (PL II. Fig. 10.) 



This restricted form of strigosa, including Cooperi, is found over all the wide 

 region indicated for the species on p. 27. The Arizona localities from which I 

 have received it are Logan, near Phoenix : Pine Creek, below Natural Bridge : 

 Huachuca Mountains. 



Var. Utahensis, Hemphill. 



For locality, see ante, p. 30. This is a rough, coarse, carinated strigosa, fig- 

 ured in Terr. Moll., V. p. 158, Fig. 66. The peristome is sometimes continuous 

 by a heavy raised callus connecting its terminations. It is sometimes smaller 

 and more elevated. 



C. SHELL LONGITUDINALLY RIBBED. 

 Var. Hemphilli, Newcomb. 



Plate II. Fig. 15. 



This form seems widely distributed. It was originally found by Mr. Hemp- 

 hill at White Pine, Hamilton, Nevada. Mr. Hemphill believes it will be found 

 all through the mountains bordering on both sides of the Snake River Valley, 

 Salmon River Mountains, Idaho. He also found it at various points in Utah 



VOL. XIII. — NO. 2. 3 



