98 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXV 
Length 8 diam. 3.3 mm., 103 whorls. Type. 
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This form resembles H. f. caneloensis, and certain specimens are 
not distinguishable; but in numerous examples opened, none had 
any lamella other than the axial. 
Holospira ferrissi fluctivaga n. subsp. Text-fig. 14. 
Debris of the San Pedro River near Mammoth, Pinal Co., Ferriss, 
1917. Type 131008. 
The shell is cylindric with a short, conic, somewhat mucronate 
summit; much like H. ferrissi, from which it differs by having the 
later whorls decidedly more convex. There are about 8 riblets 
in 1 mm. on the penult whorl. In the back and right side of the 
penult whorl there is a very strong and long parietal lamella, a 
strong, blunt axial, and a rather low basal fold. 
Length 8.3, diam. 3.15 mm.; 10% whorls. 
It stands close to H. f. sanctecrucis, but differs by the greater 
convexity of the whorls of the cylindric portion of the shell. 
A broken specimen of this species was in the shell debris collected 
by Pilsbry on the San Pedro, near Benson, in 1910. It measures, 
length 7.3, diam. 2.8 mm., 104 whorls. 
Holospira arizonensis mustang n. subsp. Text-fig 17. 
Mustang Range, Pima Co., Arizona: north side of tower, eastern 
peak, Station 153 (1918); also the following Stations of 1919: 286, 
the same as 153 of 1918; 287, a limestone hill east of 286; 332, 
main gulch of north slope of the largest mountains west of Dan 
Mathew’s ranch house, and 333, the next gulcheastward. Type 
No. 131003 A. N.S. P., and paratype in Ferriss coll. from Station 
153: 
Related to H. arizonensis mularis, but more slender; summit 
usually somewhat more slowly tapering; back of the last whorl 
more coarsely and more irregularly ribbed. Axis having a stout, 
blunt lamella. Smaller than typical H. arizonensis. 
Length 12, diam. 3.5 mm.; 133 whorls. Type. 
Holospira whetstonensis n. sp. Text-fig. 15. 
Whetstone Mountains at Stations 293, 304, 305. Type 131007. 
The shell is imperforate, long, cylindric with a rather tapering 
terminal cone about one-fourth the total length; light flesh colored. 
Sculpture of strong riblets throughout after the two smooth apical 
whorls; riblets narrower than the intervals, 40 on the penult whorl 
in the type specimen. The whorls of the cone are strongly convex, 
