152 BULLETIN OF THE 



It must be rememliererl that my figure of the dentition (PI. VI T I Fig. Pi) 

 and description of jaw were drawn from tlie Salmon River shell, nut 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 ril)s on tiie jaw. The lingual membrane has 2()-l-20 teeth, 1 1 

 laterals on each side of tlie median line. 



For the variety called Henrietta', see below. 



Triodopsis Copei, Wetiierby. 



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 ol)li(|ue lines of growth, 

 and increasing very gradually and regularly in size ; a faint cai'ina 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- 

 lai'ly and moderately imprcs.scd. Peristome subacute, and liroadly reflected 

 outward and dowuwai'd 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 poi'timi is the larger. A second tooth is carried by the inner 

 margin of tlie peristome at the centre of the Imdy wlmrl, the point of which is 

 in close relatioTi to an arcuate tooth carried by tlie jiarietal 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. (Wetherljy.) 



Ilclix Copei, WETiii.uin-, Amer. Nat, Mar., 1877, p. 



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



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

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

 with the angle of the peristome. 



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



o 



Triodopsis Henriettse, ^Lvzyck. 



Treated as a var. of T. rulfnosa, p. 313. Perliajis will prove distinct. 



Shell rimatelv umbilicated, de]U'essed, gloli.i-e, rallier snlid, willi iiunierniis 

 I'CLTular delicate stria', ilark browni-h horn-cidur ; spire obtusi' ; wlunls abdut, 

 live and a half, slightlv cnuvex ; suture deeply iiunresseil ; beneath cduvex. 



