70 PROCEEDINGS OF THE ACADEMY OF ~ [Vol. LX XV 
No. 118070 118047 118063. 118046 
Penis 9.5 10 9 9.5 
Penis-papilla 6 7 8 Tao 
Epiphallus 6 (ea E: 
Flagellum small very small 1 wanting 
Vagina q ne 9.5 ey 
Diam. of shell 27 23.5 21 25 
Station 81 54 64 57 
In No. 118070 and 118047 the basal sheath of penis is but little 
larger than the distal part of the penis. In 118063, 118067 and 
118049 it is quite thick, as in S. sabinoensis occidentalis. 
© 
Fig. 2.—Sonorella sabinoensis tucsonica. Lower ducts ‘of the genitalia, a, 
No. 118067, station 72. b, S. s. deflecta, No. 118050, station 59. c. S. s. tucsonica, 
No. 118047, station 54. d, 118063, station 64. e, 118070, station 81. fi., 
flagellum. All in the Tucson Range. 
The shell is highly variable in size and in degree of depression of 
the spire. The largest specimens, from Station 81, were found less 
than half a mile from the smallest measured above, Station 64, in 
the same valley. 
At the north end of the Tucson Range, Stations 72, 73, 79, all 
of the specimens are small and dark, diam. 20 to 21.5 mm. In the 
