1917.] NATURAL SCIENCES OF PHILADELPHIA. 97 
Oreohelix metcalfei concentrica n. subsp. Pl. VIII, figs. 1-1d. 
The shell is much more broadly and openly umbilicate than 
O. metcalfei; cartridge buff, inconspicuously mottled with gray or 
light drab, the embryonic whorls pinkish cinnamon, and the peripheral 
keel bordered below with a brown band. Sculpture of about five 
extremely low spiral cords on the base, and usually traces of two or 
three above, their intervals finely and sharply striate spirally, and 
there are very fine, irregular strize along growth-lines, sharp where they 
pass over the keel and spiral cords, elsewhere weak. The last whorl 
does not descend in front. 
Alt. 9.3, diam. 21.5 mm.; 42 whorls. 
Silver Creek, above 7,500 feet, at stations 3, 43, 7, and 11, on 
limestone outcrops. Type No. 115,755, A. N.S. P. from Station 7, 
above the box of Silver Creek, on the north side. 
In most specimens the intervals between the cords on the base are 
dull brown, or when concolored the spiral striae make them appear 
darker, giving an appearance of relief to the cords. A few individuals 
from Station 11 (a branch ravine of Silver Creek south of Gray’s 
cabin) have the base blackish chocolate. 
Specimens with the spiral cords on the base less conspicuous and 
the color usually darker—clouded and banded with dull walnut 
brown in varying degree—were found at Station 20, at the Grand 
Central Mine; Station 19, the next gulch north of that where the 
mine is; also Station 22, the succeeding gulch north (PI. VIII, fig. 1d). 
At Station 174, on the west side of Sawyer Peak about 500 feet below 
the summit, similar shells were found, varying from nearly typical 
color to broadly banded below with chocolate, the spiral cords 
therefore inconspicuous. 
Genitalia as in O. m. radiata. 
The embryonic shell (Pl. IX, fig. 10) is very beautiful. The 
first whorl is smooth, cuticular lamine along growth-lines then 
appearing gradually. From these triangular processes rise, forming 
3 or 4 spiral series above, usually 4 below a peripheral series of larger 
processes. 
The embryos of radiata, acutidiscus and hermosensis are identical 
with those of concentrica. 
Oreohelix metcalfei radiata n. subsp. PI. VIII, figs. 2, 2a, 3-83c, 6, 6a. 
The shell is more openly umbilicate than O. metcalfei, with irregular 
sculpture of strong wrinkles in the direction of growth-lines, the lens 
showing fine spiral strie between the wrinkles of the lower surface, 
very few on the upper surface. Faint traces of a few coarse spirals 
