1915.] NATURAL SCIENCES OF PHILADELPHIA. 369 
Height 7, diam. 14.2 mm.; 43 whorls. 
Genitalia (Plate XI, figs. 3, 3a).—The penis is somewhat slender, 
slightly shorter than the vagina, and a trifle longer than the epi- 
phallus. It contains a cylindric papilla nearly as long as itself, trans- 
versely wrinkled in the distal third and rounded at the end (fig. 3a). 
The retractor muscle is inserted on the epiphallus near its base. 
There is no flagellum. Length of penis 4 mm.; penis-papilla 3+ 
mm.; penial retractor 6 mm.; epiphallus 3+ mm.; vagina 53 mm. 
Dragoon Mountains, from the northern ridge of Tweed Canyon 
to the ridges facing the northern slope of the mountains; types 
No. 103,097, A. N.S. P., from Station 38. Also taken at Stations 
3, 4, 5, 10, 12, 18, 14, 15, 21, 22, 38-41. 
The shell in this extremely distinct species reminds one a little 
of Trichodiscina. There is no other Sonorella like it. The embryonic 
sculpture is a modification of the hachitana pattern. In the genitalia 
it resembles S. bicipitis of the Dos Cabezas range as much as any- 
thing. It is abundant in the northern part of the Dragoon Range, 
but Tweed Canyon apparently forms an impassable barrier to its 
spread southward. 
We rarely found Sonorella ferrissi sealed to stones, forming small 
rings. Most living ones were seen loose under stones or in the 
earth, lying with the aperture up, like Eastern Helices, and sealed 
with a somewhat convex white epiphragm. It belongs exclusively 
to the limestone terrain. 
Sonorella dragoonensis n. sp. PI. VIII, figs. 1, 1a, 1b. 
The shell is rather depressed, umbilicate (the umbilicus contained 
63 times in diameter of the shell), thin, somewhat translucent, pale 
buffy brown, with whitish bands on both sides of a chestnut-brown 
band at the shoulder. The spire is low, conic, whorls 43, moderately 
convex. First one-third whorl smooth, followed by a brief stage 
of coarse radial wrinkles, continuing longest near the lower suture, 
and succeeded by papille and short, vermiculate radial wrinkles, 
interrupted by short wrinkles in a spiral direction, which on the 
lower part of the whorl bear epidermal bristles, beginning on the 
latter half of the first whorl, and continuing throughout the embryonie 
and neani¢e stages as far as the end of the third whorl. It is suc- 
ceeded by an excessively minute vermiculate sculpture, which 
rapidly becomes fainter and disappears on the last two whorls, 
which are glossy and nearly smooth except for faint growth lines. 
Last whorl wide, descending in front. Aperture very oblique, 
round-oval. Peristome thin, very narrowly expanded throughout, 
