STREPTAXIDA. 105) 
than the other groups of the genus, in some species attaining a 
length of three inches. 
SELASIELLA, Strebel, 1878. Shell very small, glossy, vertically 
striated ; columella truncated ; labial palpi wanting. The stomach 
is simple as in Streptostyla (but is double in Glandina). 3 sp. 
Mexico. O. perpusilla, Pfeiffer. 
[ PSEUDOSUBULINA, Strebel and Pfeffer, 1882. 
Distr.—Mexico. P. Chiapensis, Pfeiffer. 
Shell turriculated, whorls numerous, narrow, the last much 
smaller than the others; columella truncated at the base; peris- 
tome simple. 
Animal without jaw. 
VOLUTAXIS, Strebel and Pfeffer, 1882. Columella with a basal 
plication. Spiraris Berendti, Pfeiffer. Mexico. 
The shells resemble Subulina and Spiraxis, but the animal has 
no jaw. | 
StreprostyLtA, Shuttleworth, 1852. 
Distr.—49 sp. Tropical America, West Indies. 
Shell oval-oblong, subcylindrical, the last whorl proportionally 
_very large, cylindrical; aperture elongated, narrow behind; 
outer lip simple, inflected in the middle; columella with a 
thickened fold at the base. 
Animal: tentacles but slightly developed, labial palpi moderate, 
foot short. 
The texture and general form of the shell do not much differ 
from some species of Oleacina, but the genus is at once distin- 
guished by its columellar fold, instead of the truncation of 
Oleacina. 
STREPTOSTYLA (restricted). Shell longitudinally striated. S. 
Nicoleti, Shuttl. 
CHERSOMITRA (Shuttleworth), Albers, 1860. Shell cylindrical, 
smooth, shining, usually yellowish; aperture more than half the 
leneth of the shell; outer lip distinctly inflected. Mexico, 
Guatemala. §S. Delattrei, Pfr. (xcii,54). Central America. 
PETENIA, Crosse and Fischer, 1868. Distinguished by the 
presence of a muciparous pore at the end of the foot ; tentacles 
and buecal lobes as in Glandina; foot truncated behind. Spire 
lengthened ; columella twisted. 8S. ligulata, Morelet. 
Famity STREPTAXIDA. 
Shell heliciform or pupiform, often with the last whorls 
obliquely deviating. 
Animal with along neck and short tail; superior tentacles 
long, narrow ; labial palpi narrow, moderate. 
