1918.] NATURAL SCIENCES OF PHILADELPHIA. 329 
Oreohelix barbata Pils. 
The occurrence of this species in the Mogollons was a surprise, 
as it was described from the Cave Creek region of the Chiricahuas, 
far to the south. It does not inhabit the dryer northern half of the 
Chiricahua range, and its distribution is therefore conspicuously 
discontinuous. It evidently changes much more slowly than the 
Ashmunellas, though some little differentiation may be seen as noted 
below. 
In Dry Creek, it was taken in the slides with Ashmunella, at Stations 
62, 64, 68, 70, 72, 75, 77, 78 and 79. In most of these colonies it 
reaches large size, even larger than in the Chiricahuas. Two examples 
from Station 79 measure: height 8, diam. 16 mm., and height 9, 
diam. 15.4 mm. Usually there are several circular fringes on the 
last whorl above the periphery, and more on the base than in Chiri- 
cahua examples. In the latter, fringes above are exceptional. Count- 
ing that at the periphery, there are usually 8 to 11 spiral wreaths in 
Dry Creek barbata, 6 to 10 in Chiricahuan specimens. In some lots 
the cuticular appendages are mostly or quite lost in the adult stage. 
Some consist partly of smaller individuals; and at Stations 64 and 75 
all are small, 11-12 mm. in diameter. 
Cave Spring Canyon, Station 57. Very small, about 10 mm. 
diameter, and agreeing well with O. b. minima P. & F. (Proc. A. N.S. 
Phila. 1910, p. 94, fig. 15) from Rucker Canyon, Chiricahuas. There 
is probably no direct relationship, each being presumably a dimin- 
utive race of the normal larger forms of their respective ranges. 
These small forms show decadence by the deep descent of the last 
whorl to the aperture. 
Willow Creek, Station 46. This is on the eastern slope of the Mo- 
gollon watershed. The size is small, diameter about 11mm. Cutiec- 
ular appendages usually deciduous. 
Thysanophora hornii (Gabb). 
Arizona: Station 45 (1913), John Lyon’s Mountain, north of the 
Little Dragoons. Blue River, Station 18 (1914), and Little Blue 
River, Greenlee Co. 
New Mexico: Station 76, Dry Creek, west side of the Mogollon 
Mountains. 
Thysanophora ingersolli (Bld.). 
Arizona: Reservation Creek, 9,500 ft.; Fish Creek; Horseshoe 
bend of Black River, and 2 miles above, at 9-10,000 ft. Apache Co. 
Cosper’s pasture, Graham_Co. 
