284 PRUCEEDINGS OF THE ACADEMY OF [Mch., 
the middle of the upper surface and another immediately below the 
white keel, the early whorls dull brown; without perceptible cuticle. 
Sculpture of close but irregular and rather sharp growth-wrinkles, very 
indistinctly decussated with spiral strie. The embryonic shell consists 
of only 14 whorls. The first half whorl is nearly smooth, the next 
whorl is sharply and finely but very regularly ribbed radially. With the 
compound microscope some very weak spiral striation may be seen in- 
distinctly in the intervals. At the end of the embryonic period the 
rib sculpture abruptly gives place to a lower, less regular oblique 
striation. The spire is convexly conic. Whorls 5, convex, impressed 
above the suture, where the keel projects a trifle. At the periphery 
the keel projects somewhat, the surface being a little concave above and 
below it. Base convex. Aperture small, oblique, a little angular at 
the outer part. Lip simple, the ends approaching. 
Alt. 6.5, diam. 11 mm. 
6s ‘B cc 10.5 * 
Cave Creek Canyon, Chiricahua Mountains. Types No. 87,012, 
A. N.S. P., collected by James H. Ferriss. ‘Occurred on a dry, clay 
hillside, under dead vegetation and stones, and was found nowhere 
else on the mountain.” 
This is a very distinct little species, closely related to O. avalonensis 
Hemphill of Santa Catalina Island, California, which has an apex of 
the same type. O. avalonensis differs, however, by its conspicuously 
decussate surface, wider last whorl and larger aperture, and it has a 
half whorl less. It is figured for comparison, Pl. XT, figs. 4, 5, 6, 7. 
The umbilicus is about equal in the two species. 
QO. chiricahuana differs conspicuously from O. yavapai and O. y. 
neomexicana by its peculiar apical sculpture, ete. 
The genitalia are figured (Pl. XIX, fig. 4). The penis is cylindric, a 
little flattened and protruding on one side at the distal end. The epi- 
phallus is longer than the penis, club-shaped, the retractor inserted 
upon it not far from its base. The lower part of the spermatheca duct 
is enlarged and muscular. The lengths of the organs are as follows: 
penis 4, epiphallus 4.7, vagina 3.5, spermatheca and duct 7.5mm. The 
foot is scarcely granulose, the integument smoothish, tessellated in 
rather coarse pattern with blackish or gray spots. No genital furrow 
is visible. The mantle edge is thin. 
The jaw (Pl. XXIII, fig. 24) is striate, somewhat less arcuate than 
that of O. clappi. 
The radula (Pl. XXII, figs. 10, 11) has 26.1.26 teeth. They are 
rather shorter than usual in Oreoheliz. The central and lateral teeth 
