1910.] NATURAL SCIENCES OF PHILADELPHIA. 61 
quent whorls are lightly marked with growth-lines only. The aperture 
is very oblique, subcircular ; peristome thin, a little expanded, narrowly 
reflexed below, the columellar margin dilated. Alt. 15, diam. 24 mm. ; 
alt. aperture 11.7, width 13 mm. 
Penis small, usually shorter than the vagina, and less than one-third 
as long as the spermatheca and duct. Epiphallus short, the flagellum 
apparently absent or reduced to a very minute adnate coecum (pl. IV, 
figs. 1, 2,3, 4,5,7). Radula with 35,1, 35 (summit of Cross J Mt.) 
+o 38,1, 38 teeth, about 14 laterals, an ectocone appearing on the 
11th to 13th. The entocone is bifid on the outer 15 to 18 marginals, 
and the ectocone occasionally so on some teeth, though generally 
simple. Six radule from 5 stations examined. The jaw has 5 ribs in 
two, 6 and 7 in two other examples. The crops and cesophagus as far 
as the stomach are conspicuously sulcate or corrugated longitudinally. 
Type locality, head of Big Emigrant Canyon at Station 1, on a steep 
slope shaded by pinyons, under large stones (limestone). The species 
occurs in numerous colonies throughout Big Emigrant Canyon, except 
on slopes with southern exposure. See map on p. 121. 
This handsome species, like others of the hachitana group, 1s ill- 
characterized as far as the shell is concerned, but the genitalia are 
characteristic by the small penis and absence of a free flagellum. In 
the Chiricahua Mountains it 1s related to S. bicipitis of the Dos Cabezas 
range, but in that the penis is well developed and the flagellum, though 
small, seems to be invariably present. In all of the numerous exam- 
ples opened the crop and intestine to the stomach are deeply furrowed 
longitudinally, a condition observed in no other Sonorella. To what 
extent this corrugation may be due to the state of the specimens 1s 
uncertain. It happened that by some unaccountable oversight all 
of the Big Emigrant Sonorellas were cooked and pulled without 
drowning, and then were preserved in alcohol too strong to give the 
best results. 
All of the following colonies but one are on limestone. 
Type locality, Station 1. Thirty adult specimens were taken, ten 
of them alive. They measure as follows: 
Diam. in mm........ 26 25r a 225 25 25 25 2A. & “24.8 
Al\Gmin mm............ Loar ae 1Gn3> ARO ee A Zale 15 
Diam. in mm........ DAR SoA ae’ of) (24D 2a 2. 2A 24 
24) Seis ate 00) 00 eee 15 Oe 4, wlo 14 16 15.2 
Diam. in mm........ 24 (three) 24 24 24 (three) 23.3 23 
Ae WAM......00.. 15 14.5 14.3 14 14 14 
