HELIX. 135 



front and constricted behind the lip, periphery angulated; umbilicus 

 expanded and grooved, with a minute central perforation; aperture 

 extending from the periphery to the umbilicus, somewhat ear-shaped, 

 lip white, expanded, its extremities connected by a V-shaped parietal 

 tooth, the two laminae of which run far within the shell, upper 

 portion of the lip with an entering angle, basal portion callous and 

 reflected. Diam. 12 mill. 



New Braunfels, Texas. 



H. MOOREANA, W. G. Binney. PL 28, figs. 16, 14, 15. 



Depressed, carinated, white, strongly striate above and nearly 

 smooth beneath; spire somewhat raised, suture deep; whorls 6, the 

 last much deflected at the aperture, umbilicus exhibiting 1 whorls; 

 aperture semi-oval, lip broad, heavy, but slightly reflected, with 

 two marginal teeth of which one is basal and the other sub-basal, 

 parietal tooth large, rhomboidal. Diam. 10 mill. 



Texas. 

 Var. THOLUS, W. G. Binney. Figs. 14, 15. 



Umbilicus wider, showing 2J whorls, lip narrower, tooth of outer 

 lip situated higher. 



H. TEXASIANA, Moricand. PI. 28, figs. 17-19. 



Orbicular-depressed, rather solid, ridged above, smooth below, 

 suture moderately impressed: whorls 5, slightly convex above, 

 periphery subangular, deflected in front, base convex; aperture 

 crescentic, the lip-margins joined by a large V-shaped parietal tooth, 

 outer lip with two closely placed denticles, with a pit between them ; 

 umbilicus minutely perforate ; pale horn color. 



Texas, Mexico. 



H. Tamaulipasensis, Lea, is a synonym. 



H. TRIODONTOIDES, Bland. PL 28, fig. 20. 



Perforate, orbicular, depressed, thin, subpellucid, obsoletely striate 

 above, smooth beneath; whorls 5, somewhat convex, deflected in 

 front, subangulate on the periphery, and very convex below ; aperture 

 obliquely lunate, the extremities of the reflected lip connected on 

 the body whorl by a V-shaped tooth, the lip having two small teeth, 

 far apart, one on the outer margin of the aperture, the other on the 

 base; pale horn color. Diam. 9'5 mill. 



Texas. 



More delicate, not as distinctly ribbed, more elevated than 

 H. Texasiana; the teeth also are smaller, and farther apart. 



