PERIDERIOPSIS. 241 



columella fleshy or brownish rose-color. Surface marked with 

 distinct, irregular growth-wrinkles and fine, subobsolete 

 spiral striaa. Spire a little convexly conic, slightly contracted 

 near the obtuse apex. Whorls 7%, convex, the suture mar- 

 gined below, the border beaded on the last whorl or two, 

 almost smooth on earlier whorls. Last whorl well rounded 

 throughout. Aperture oblique, irregularly ovate, excavated 

 and subangular in the middle of the left margin, white 

 within ; peristome simple, somewhat thickened within. Colu- 

 mella vertical, nearly straight, flesh-colored, somewhat thick- 

 ened and round-edged, not truncate below. 



Length 45, diam. 20.5, apert. 18.5 mm. 



Length 54-65 mm. (Chaper). 



West Africa: Cape Palmas (M. Verdier). 



Perideris verdieri CHAPER, Bull, de la Soc. Zool. de France, 

 x, p. 45, pi. 1, f. 5 (1885). ?KOBELT, C. Cab., p. 30, pi. 3, 

 f. 5, 6. 



A solid species, distinguished by the flesh-colored colu- 

 mellar area. The last whorl is not so wide as in P. bifrons 

 or reeveanus, and there is no tendency whatever to be an- 

 gular at the periphery. Fig. 68 is copied from Chaper. 

 Fig. 69 represents a typical specimen in coll. A. N. S. 



Genus PERIDERIOPSIS Putzeys, 1898. 



PUTZEYS, Proces-verbaux des seances de la Societe Royale 

 malacologique de Belgique, January 8, 1898, p. vi. Type 

 P. umbilicata. 



The shell is similar to Pseudotrochus in the obtuse apex, 

 smooth apical whorls and generally smooth surface, more or 

 less angular periphery, and angular-ovate aperture ; the outer 

 lip is simple, more or less thickened within; columella ver- 

 tical and nearly straight, hardly truncate at base, its edge 

 refiexed but not closing the umbilical fissure; general shape 

 ovate-turrite. Axis perforate. Type P. umbilicata. 



Distribution, Congo valley. The beautifully colored shells 

 of this group resemble such Pseudotrochi as P. auripigmen- 

 tum, but differ in the perforate axis and open umbilical 

 crevice. The spire is also rather more lengthened, and the 



