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1909.} NATURAL SCIENCES OF PHILADELPHIA. 503 
of the Huachuca range. It differs from S. granulatissima chiefly 
in the genitalia, the larger penis and the shape of the vagina being 
constant features in the series of both species dissected. Specimens 
have been dissected from five lots, from the head of Bear Canyon 
(fig. 7), east fork of Cave, and from Miller Peak (fig. 5). One individ- 
ual of several from the latter place seems to have the very minute 
bud-like vestige of a flagellum. 
The shell will be recognized by its yellow, glossy surface and depressed 
shape. The brownish forms from Ida and Ash Canyons, mentioned 
above, require more study, with better fresh or alcoholic material than 
we can command at this time. One from Ash Canyon is figured, fig. 18. 
Named in honor of Mr. L. E. Daniels, who accompanied Mr. Ferriss 
in the expedition of 1907. 
Genus ASHMUNELLA Pils. and Ckll. 
The Ashmunellas of the Huachuca range, while very diverse in 
appearance, belong to a single closely related group. Probably all 
descended from an ancestral stock not unlike A. levettei angigyra, the 
most widely distributed form, and the one showing most affinity to 
species of the Chiricahua and other ranges. The common ancestry 
of the whole series is demonstrated by the intermediate stages found 
among the shells, and by the soft anatomy, which is so much alike in 
all that it would probably be impossible to tell the species apart 
without the shells, yet differing characteristically from the soft parts 
of all Ashmunellas of the Chiricahuas or other ranges by the sacculated 
or varicose spermatheca and the shape of the penis. 
The species and races form a beautiful chain of variations, pretty 
completely connecting those having most complicated apertures with 
those in which the aperture is toothless, thus: bifwrca—levettei— 
ursina—heterodonta—varicifera. 
Evolution has proceeded from fully toothed apertures towards 
toothless apertures. In other words it has been retrogressive, marked 
by degeneration of complex structures. 
Soft Anatomy of Ashmunella.—Time has not admitted a full exami- 
nation of the anatomy, but the genitalia of many individuals have been 
studied. These organs are so similar in all of the forms that one 
description will suffice. The penis (P.) is rather large for an Ash- 
munella. Inside it has six unequal fleshy longitudinal ridges, inter- 
rupted in the middle (pl. XX, fig. 6). This point is marked exter- 
nally by a slight constriction. The epiphallus (ep7.) is very long, 
terminating in a minute flagellum (7l.). The retractor muscle (rp.) 
