ay 
rn oh 
1910.] NATURAL SCIENCES OF PHILADELPHIA. 59 
2h CA es DIRT 2s2 nes te, 12 bias) Sie Sai 
Piertnien Ane ste. 21 Zak 20.5 20 19.2 19 18.5 mm. 
Ten adults from the slopes around the head of the southeastern 
branch of Buckeye Canyon, Station 4, vary from 18.7 to 22 mm. 
diameter (No. 94,325). 
Thirteen adults were taken at Station 5, near the head of Happy 
Camp Canyon, only one alive. 
1 aera! 13 13 12.6 ips 12.3 ial 11.7 mm. 
Wram............ 22.0 21 2087 20 20.2 20 19 mm. 
Bee olere iil i ne? 11 10.5 mm. 
Len 1932 1922) wo 19.2 19 18 mm. 
At Nine-mile Water-hole we obtained a single living adult snail and 
8 young (No. 99,324). These, with a specimen taken by Mr. Ferriss 
in 1905, indicate a large race at this place, with a slightly larger umbili- 
cus than the types, and more closely approaching lip-ends (pl. I 
figs. 4, 5). The soft anatomy, sculpture and color are like typical S. 
bicipitis. Whorls barely 5. Two adults measure: 
SPAMMER ER At EOIN bays dsc Odo ros we Roe le Wn ee 15 15° mm. 
“Sereda TULL a ai EAS ie eee ea i nee ees S220) OA Gaia 
SSSA NGS a ee ee ee eR EEE Ec 13 13 a 
ts Glam /s...)... ios ola Monk odes eae eae eae ee ‘ane ier 14 A ein 
The genitalia are figured pl. LII, fig. 2. : 
Nine-mile Water-hole is a shallow amphitheatre open eastward to 
the mesa, its slopes covered with great weathered boulders of coarse- 
erained light gray granite, among which ferns grow luxuriantly. 
A tiny stream trickles among the rocks, collecting into a stagnant 
pool at the base. A man can make his way in the interstices between 
and under the rocks, in some places, but as very few of them are 
movable, it is almost impossible to obtain the shells. 
Specimens were dissected from Stations 1, 3, 4,5 and from Nine-mile 
Water-hole. All have a distinct sheath at the base of the penis, 
attached also to the epiphallus and partially enveloping the latter 
throughout a part of its length. This sheath varies from about one- 
third the length of the penis in the type lot, to about a half in that 
from Nine-mile. The penis-papiila in transverse section (fig. 7, pp.) 
shows a group of minute ducts, but there seems to be a single terminal 
orifice. The vagina is longer in the types than in other lots ex- 
amined. 
