58 PROCEEDINGS OF THE ACADEMY OF [Feb., 
Nine-mile Water-hole, living deep under stones and rocks. Buckeye 
Canyon is the first from the northern end of the range. Its upper 
branches drain the eastern flanks of Dos Cabezas Peak. At the time 
of our visit in November there was water at intervals in the stony 
bed of the canyon as far down as our camp, near the reduction plant 
of the Buckeye gold mine. Tarbox and Happy Camp Canyons unite 
into a wide valley about a mile from the mesa. The mouth of this 
valley is half closed by a great reef of light gray granite rocks which 
forms a conspicuous landmark from the mesa. The country rock of 
these canyons is mainly metamorphic, but in part granitic. 
This species has the same apical sculpture as S. bowiensis and 
S. optima. It differs from optima in the shape of the penis-papilla, 
the presence of a flagellum, the shorter inner cusp of the marginal 
teeth, the larger aperture and narrower umbilicus. S. hachitana 
from the Big Hachet Mountains has a decidedly smaller aperture. 
In shell characters S. bicipitis stands nearest S. huachucana, but the 
apical sculpture of the latter is much less distinct, without the oblique 
threads on the last embryonic whorl which are characteristic of S. 
bicipitis and related forms. This species is represented by 48 adult 
shells, of which 17 were taken alive, and many young ones. The 
colonies are widely separated’’ and small; living shells are rare, and 
their collection involves the removal of much rock. The physical 
conditions are very similar in all the stations in Buckeye and Happy 
Camp Canyons. All the stations are on steep well-drained slopes 
facing northward, the earth very dry (in November), even under a 
couple of feet of rock, and scantily protected by low scrubby oak 
brush. At Nine-mile Water-hole the conditions are quite different 
as noted below. 
In the type locality, Station 1 (pl. I, figs. 1, 2, 3, and pl. ITI, fig. 7), 
we took 7 living adult and 6 young specimens measuring as follows: 
TTA ot ions on at ann 18 la 14 AS BS 1S ae 
ID Dairy Fatt a Me re che 24 Paro. Zo. 22... 22> (21°) Qiao wine 
This station is high on the steep south side of the canyon. 
In a lot of 23 from Station 3 (No. 94,326), 7 are adult living shells, 
measuring : 
17 This must be understood in a comparative sense, as indicating that many 
apparently suitable situations examined were found barren. Doubtless a 
longer search would show that a large number of small colonies exist. We 
worked two days in Buckeye and several hours in Nine-mile. 
