192 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
outer lip patulous behind and then receding to the suture, forming 
a shallow sulcus, more or less reflexed below, the margin contin- 
uous across the body with a groove behind it and a rather rude thin 
layer of callus covering the umbilical region; the inner part of the 
lip is white and somewhat thickened, in colored individuals the color 
appears in the throat and with emphasis; the base is full and 
rounded, the periphery destitute of any keel; there is more or less 
variation in size, extremes measuring: 
Height Max. diam. Min. diam. Aperture 
10.0 12.5 9.5 6.0 mm. 
8.5 11.0 8.0 5.0 mm. 
The outer surface of the operculum is rudely striated, the inner 
polished, the color varies with that of the shell. It is solidly cal- 
careous. 
Habitat—In the Alvarez Mountains with the preceding species 
and at San Dieguito, San Luis Potosi. 
Type, No. 110,397 U. S. Nat. Museum. 
The species approaches S. pannucea Morelet, and S. alata Menke, 
is more elevated than the former and less so than the latter. The 
sutures are less deeply impressed than in alata which seems its 
nearest relative. The superior sinus seems less deep than in either of 
the species with which it is above compared, but this feature varies 
with age. Many of the specimens had been opened by mice who 
extract the animal through a neat little hole in the side of the shell! 
as they would take a kernel from a nut. 
HELICINA ZEPHIRINA Duclos 
Habitat.—Alvarez Mountains, San Luis Potosi, with the pre 
ceding. 
HELICINA ELATIOR von Martens 
Habitat——With the preceding and also at San Dieguito. 
According to Dr. Pilsbry this is Helicina zephirina Duclos, var 
elatior.von Martens, the H. turbinata Pfeiffer as of Wiegmann, but 
not the H. turbinata of Sowerby. A large series having been ob- 
tained, it is quite evident that it is entirely distinct from H. zephi- 
rina, and therefore von Martens’ varietal name may be raised tc 
specific rank. 
PLANORBULA OBSTRUCTA Morelet 
Quite a number of specimens were obtained from a small pool ir 
the same vicinity as the preceding species and that which follows. 
