1903.] NATURAL SCIENCES OF PHILADELPHIA. 783 



Since the publication of my description I have obtained specimens 

 of S. minuscula (Pfr.), one of which is figured for comparison (PI. LI, 

 fig. 3). S. fragilis is much more depressed than minuscula, with more 

 distinct spiral lines when the hairs arc rubl^ed off. The two species 

 are quite distinct. 

 Schasicheila vanattai Pils. PI. LI, figs. 5, 5a. 



Proc. Acad. Nat. Sci. Pliila., 1899, p. 391. 



Same locality as the preceding, with which it occurred. Readily 

 distinguished by the strong peripheral angle. The sinus is slightly 

 deeper than in S. fragilis. 

 Schasicheila vanattai tricostata subsp. nov. PI. LI, fig. 4. 



Last whorl with three large obtuse rounded carinae or spiral ribs, 

 the surface concave between them and below the lower one ; cuticular 

 spirals weakly developed. Pale yellowish-corneous. Whorls 3^. Alt. 

 3.7, diam. 4.5 mm. 



Caiion 4 miles west of Victoria, Tamauhpas. Type No. 85,908, 

 A. N. S. P. 



One adult and one immature specimen collected. In the absence of 

 a series sufficient to show whether the remarkable features above de- 

 scribed are constant, I prefer to rank this as a variety of S. vanattai. 

 No other known Schasicheila has spiral ridges and sulci of this kind. 



Schasicheila hidalgoana Dall. PI. LI, figs. 8, 8a. 



Schazicheila hidalgoana Dall., Nautilus, XI, p. 62. 



Shell depressed, conoidal above, convex beneath, strongly angular 

 at the periphery. Yellowish-corneous, usually pink toward the apex, 

 under a thin brown cuticle, which is very densely and minutely rough- 

 ened by close cuticular spiral threads, conspicuously longer ones fring- 

 ing the periphery. These cuticular processes hold sufficient dirt to 

 make the whole surface of fresh shells blackish. Under the cuticle 

 the surface is glossy, striatulate obliquely, and densely striate spirally. 

 Whorls 4;V, slightly convex, the intermediate ones with an impression 

 above the suture. Last whorl wide, strongly angular peripherally, 

 a little impressed in the middle of the base. Aperture of the usual 

 half-rotund shape, the outer lip narrowly expanded, with a deep tri- 

 angular excision or notch above. Umbilical pad small and somewhat 

 sunken. Operculum with processes ])rojecting Ijcyond the lip at both 

 base and upper sinus; bluish gray, indistinctly roughened externally. 



Alt. 9, diam. 14 mm. 



Alt. 8.7, diam. 12.3 mm. 



Canon 4 miles west of Victoria, State of Tamaulipas. No. 85,919, 

 A. N. S. P., collected bv S. N. Rhoads. 1903. 



