1905. ] NATURAL SCIENCES OF PHILADELPHIA. 283 
I have partially examined the internal anatomy of one of the speci- 
mens from Beulah. The penis (Pl. XIX, fig. 9) is bent in the middle, 
the lower half a little swollen, with muscular walls, the upper half 
slightly smaller, softer. There is a very small apical papilla, and the 
retractor muscle is inserted at the apex of the penis and root of the 
epiphallus. The epiphallus is large, shorter than the penis, and the 
vas deferens enters at the side, not the center of the apex. 
The radula has 19.1.19 teeth, similar to those of O. yavapai. On the 
fifth or sixth teeth the ectocone is developed. Marginals bicuspid, as 
usual. 
Subgenus RADIOCENTRUM nov. 
Oreohelices with an embryonic shell of 14 radially ribbed whorls, 
spiral striz in the intervals between ribs excessively weak or wanting. 
Penis rather short, with a hollow dilation at the distalend. Epiphallus 
club-shaped, as long as the penis, the retractor inserted near its base. 
Type O. chiricahuana Pils. 
This group differs from Oreohelix by the smaller number of embryonic 
whorls and their different sculpture, and in the somewhat different 
structure of the penis. It includes at present three species: O. chiri- 
cahuana, O. clappi and O. avalonensis. 
The genitalia are similar in the two species examined, the only 
difference being in the shape of the distal end of the penis, and in the 
absolute dimensions. ‘The pallial organs of O. clappi do not differ from 
those described above for Oreohelix strigosa. 
Key to Species of Radiocentrum. 
a.—Shell bluntly subangular or almost rounded at the periphery; coy- 
ered with a green or olive cuticle, largely worn from old shells. 
Alt: 8.5 to 9.7,diam.15mm., . . . O.clappi Ferriss. 
a’.—Shell carinated ; - earthy, without perceptible cuticle. 
b.— Whorls 4h, granulated above and below, the last one wide; 
aperture large. Alt. 6, diam. 11 mm.” \(H emphill). 
O. avalonensis Hemphill. 
b’.—Whorls 5, striated but not granulated, slowly widening; 
aperture small. Alt. 6.5, diam. 11 mm., 
O. chiricahuana Pils. 
Oreohelix chiricahuana n.sp. PI. XI, figs. 1, 2, 3. 
The shell is depressed, the altitude about .6 of the diameter, about 
equally convex above and below the peripheral keel. Umbilicus rather 
well-like, slowly contracting, and contained five or six times in the 
diameter of the shell. Whitish, with an indistinct gray band near 
