152 BULLETIN OF THE 



It must be remembered that my figure of the dentition (PI. VIII. Fig. R) 

 and description of jaw were drawn from the Salmon River shell, not the typical 

 shell found only in the Sierra Nevada region at " Big Trees." 



Triodopsis vultuosa, GOULD, (p. 312.) 

 Plate III. Fig. J. 



There are 12 ribs on the jaw. The lingual membrane has 20-1-20 teeth, 11 

 laterals on each side of the median line. 

 For the variety called Henrietta;, see below. 



Triodopsis Copei, WETHERBY. 



. Plate I. Fig. J. 



Shell reddish, somewhat thin, deeply striated by lines of growth, and of 

 medium size. Spire somewhat depressed in some specimens, slightly more ele- 

 vated in others. Whorls 5, transversely striated with oblique lines of growth, 

 and increasing very gradually and regularly in size ; a faint carina appearing 

 at the junction of the upper third and lower two-thirds of the body whorl, 

 from which the latter tapers inwardly to the base of the shell. Sutures regu- 

 larly and moderately impressed. Peristome subacute, and broadly reflected 

 outward and downward at the lower two-thirds, and bearing on its basal third 

 an acute carina, within which is seen a prominent, vertical, double tooth, of 

 which the outer portion is the larger. A second tooth is carried by the inner 

 margin of the peristome at the centre of the body whorl, the point of which is 

 in close relation to an arcuate tooth carried by the parietal wall of the aper- 

 ture. Umbilicus wide, exhibiting most of the volutions. Height, 7 mm. ; 

 greater diameter, 14 mm. This size is about the average. (Wetherby.) 



Helix Copei, WETHERBY, Amer. Nat., Mar., 1877, p. 



Twenty miles north of Beaumont, Harden Co., Texas. 



It is very like a large vultuosa, the aperture not produced beyond the teeth 

 as in Henriettce, but there is no trace of the callus connecting the parietal tooth 

 with the angle of the peristome. 



The figure on Plate I. is a fac-simile of that of Prof. Wetherby. 



Triodopsis Henriettae, MAZTCK. 



Treated as a var. of T. vultuosa, p. 313. Perhaps will prove distinct. 



Shell rimately umbilicated, depressed, globose, rather solid, with numerous 

 regular delicate strise, dark brownish horn-color ; spire obtuse ; whorls about 

 five and a half, slightly convex ; suture deeply impressed ; beneath convex, 



