1910.] NATURAL SCIENCES OF PHILADELPHIA. 101 
there are more ribs on the jaw. The shell is cormeous-brown, sub- 
acutely angular at the periphery, the angle weakening on the last part 
of the whorl, behind the lip, where the surface is more strongly striate. 
Spire convex. There are 6} to 64 very slowly widening, slightly 
convex whorls, the last descending somewhat in front. The aperture 
has a rather long, concave-topped tooth within the outer lip, its face 
concave. The basal lip has two tubercular teeth, a little compressed 
laterally, the inner one smaller. These teeth divide the lower border 
of the aperture into three nearly equal bays. The parietal tooth is 
straight or slightly bent inward at the axial end; never V-shaped, as it 
frequently is in A. fissidens. Parietal callus thin. The umbilicus is 
rather wide, contained 4% times in the diameter of the shell. The 
surface is rather dull, finely striate, the strize appearing more or less 
Fig. 17.—Ashmunella proxima, Quartzite Peak, Station 1. 
irregular or interrupted under a strong lens. The size varies little 
from 12 mm. diameter. 
In perfectly fresh young shells a delicate pattern of minute low 
granules on the upper surface may be seen with some difficulty. Some 
very weak traces of spiral strie may sometimes be made out on the 
base. The young shells have a callous rib within the lip, at resting 
stages, but it is apparently not formed as frequently as in A. fissidens. 
The genitalia were figured in 1905, pl. 21, fig. 24. Having again 
examined the individual dissected, we note that the penis was incor- 
rectly drawn. The swollen basal half is everted (as in pl. 21, fig. 23), 
hence does not show in the figure. The slender upper portion of the 
penis is shown, its distal end indicated by a slight node, only indis- 
tinctly drawn in my figure. With these corrections, it will be seen 
that the organs are like those of emigrans, fissidens and albicauda, 
