[122] 



6. Thaumastus Schiedeanus, Pfeiffer. 



Plate 14, figures 1, 2, 4, 5. 



Ovate-conic, thick, irregularly longitudinally striate, narrowly 

 umbilicate ; whorls 6|, slightly convex, the last large ; aperture 

 oblong-oval, lip simple, a little expanded, thickened within, 

 columellar margin reflected, columella more or less plicate. 

 White, brownish inside. 



Length 31, diam. 17 mill. 



Texas and Mexico. 



This species appears to vary considerably in form, some spe- 

 cimens being longer and less inflated than the type, and being 

 obtusely angulated on the periphery. A young shell of this 

 character is copied from W. G. Binney (fig. 2), who proposes, 

 should it prove to be distinct, to call it Mooreanus. I add an older 

 specimen, of the same form (fig. 4), but without the coloration of 

 Mr. Binney's shell ; it is from Brownsville, Texas. Fig. 5 repre- 

 sents a not unusual variety with distinct columellar tooth, which 

 Pfeiffer supposed distinct, and proposed to call JBuUmus Binney- 

 anus. The examination of many shells showing the transition 

 from a smooth to a toothed columella, convinces me that they 

 are all of one species. 



7. Thaumastus Marise, Albers. 



Plate 14, figure 3. 



Oblong conical, solid, rather smooth, narrowly umbilicate; 

 spire conical, acute ; whorls 6J, slightly convex, attenuate at 

 the base ; aperture acuminately oblong, oblique, lip sharp, 

 columellar margin dilated and reflected, columella with a small 

 tooth. White, with obsolete brown spots and dashes, brown 

 within. 



Length 33, diam. 14 mill. 



Texas. 



MORMUS, Albers. 

 1. Mormus sufflatus, Gould. 



Plate 14, figure 6. 



Ovate, slightly striate, thin, slightly perforate ; spire short ; 

 whorls 5|, the last elliptical, and equalling three-fourths of the 

 total length ; aperture lunate, lip simple, columella reflexed. 

 White. 



Lenigth 33, diam. 17 mill. 



Lower California. 



