102 PROCEEDINGS OF THE ACADEMY OF [Feb., 
The mantle within the last whorl is white, with the anterior vessels 
of the lung faintly traced in gray and having gray pigment along the 
periphery. 
Southern forms resembling A. procima.—Raspberry Gulch. A few 
specimens in poor condition are intermediate between proxima and 
fissidens as to the basal teeth, but the umbilicus is much narrower than 
in either, and the peripheral angulation is less pronounced, thus 
approaching A. duplicidens. There are over 6 whorls. Other southern 
localities for forms of A. proxima are Rucker Canyon and “Turtle 
Head,” a station between Crook’s Peak and the mouth of Rucker. 
A. fissidens should by rights be subordinated to proxima as a sub- 
species, on account of the various intermediate forms; yet the status 
of the races can be more clearly expressed by the artificial device of 
making it a ‘“‘species.” 
Ashmunella proxima emigrans n. subsp. Fig. 18. 
On Big Emigrant Mountain, Big Emigrant Canyon, a race was found 
having some characters of A. fissidens. The shell is somewhat larger 
Fig. 18.—A. p.emigrans. A,C,apertures of adult shells. B, young shell 11 mm. 
diam. Big Emigrant Canyon. 
than proxima, more robust, with slightly less than 6 whorls. The 
two basal teeth are less separated, somewhat united by a callus at 
their bases, and the inner one is generally smaller, frequently very 
small. There is often the weak trace of an upper branch, making the 
parietal tooth V-shaped. Fine spirals may be seen on the base of 
the shell. The young shell forms a very strong callous rib within the 
lip, as in A. fissidens. The umbilicus is narrow, contained five times 
in the diameter of the shell. Alt. 5.8, diam. 13.2 mm. 
This shell is like A. fissidens except in the single character of having 
the basal teeth more widely separated. As in that species, the inner 
of the two basal teeth is quite variable in size. It is a race intermediate 
in character between fisstdens and proxima. 
