1915.] NATURAL SCIENCES OF PHILADELPHIA. 379 
parietal lamella when present is very small, and most specimens lack tt. 
They are very uniform in size and sculpture, in a long series taken. 
Length 8.7, diam. 3.2 mm.; whorls 10; lamelle 1 
“ce Sc0, ce 3 “ ce 103; ce 2 
ce 8.1, cc 3 a3 a3 103; iz D). 
ce 7.9, ce oD (as ce 4; cc il 
ce co, ce 3 ce ce 3. cc il 
ce (ay ce 3.1 cc ce 4; ce 1 
ce a0, ce 3.1 ce is 93; ce 1 
ce 7 ce Sil ce ce 9; ‘ 
Holospira campestris cochisei n. subsp. PI. XIV, figs. 6 to 8b. 
Similar to campestris, but more slender, with fewer ribs (28 to 40 
on the penultimate whorl, in the type lot), the intervals wider. 
Internal lamellee three, the parietal very long and strong. 
Length 10.5, diam. 3.8 mm.; whorls 12; lamelle 3. 
“cc 1 73 ell “ce 73 = ; 
3 fee fh. 95 
ce 9.8, a3 241 “ ce 113; cc 3 
igs 9.7, a3 3 i! ce ce iL: ce 2 
“ce 9.6, ce 3 1 ce ce is: ce 3 
“ 9.3, “ 21 Ts “ ti: “ = 
ce 8, ce 3 1 ce iz iO); a3 3 
Dragoon Mountains: along the sides of an arroyo or gulley on 
the mesa within the wide mouth of Tweed Canyon, Station 16; 
Types No. 112,219, A. N. S. P. Also Stations 17, 19-23, and 27, 
all in Tweed Canyon. 
The type locality, Station 16 (Pl. XIV, figs. 7—7f), is on the sloping 
sides of the arroyo, which is about 15 feet deep, and meanders across 
the mesa. Near the mountain the gully deepens to 30-40 feet, the 
sides become subvertical, and Holospira disappears. The mesa is 
grassy with some bunches of bear grass. There are some small oaks, 
juniper, catclaw, etc., in the arroyo. The shells are found under 
dead sotol and sometimes stones, etc. They reappear just below 
the igneous dyke near the base of the mountain, Station 17, but do 
not cross the dyke. Several other arroyos in the same plain were 
not examined, and there are doubtless many Holospira colonies in 
the neighborhood. 
Station 19, on the slope near foot of mountain, below the igneous 
dyke. The shells resemble types of H. c. cochisei except that they 
are more finely, closely ribbed, ribs 45 to 50 on the penultimate 
whorl. Ten specimens opened are trilamellate. 
Station 20. Mouth of second ravine west from granitic spur. 
