68 TRYONIA. 
2. TRYONIA PROTEA, Gould. 
Plate 17, fig. 21. 
Shell elongate, slender, whorls seven to 
eight, moderately convex with well impressed 
sutures, cancellated by longitudinal and re- 
volving ridges; aperture small, ovate. 
Alt. 7:5, diam. 2°5 mill. 
Colorado Desert, Southern California. 
Differs from No. 1 by its cancellate surface, 
destitute of ribs. 
Mr. Conrad described this same species un- 
der the name of Melania exigua, and the date 
of the publication is given as one month earlier 
than that of Dr. Gould, but I agree with Mr. 
Binney, that there is scarcely a doubt but that 
the latter date is a false one, and Dr. Gould’s 
name was the one really first published. 
(49) 
