PSEUDOTROCHUS. 225 



migcrus Fer., Moll. t. 118, f. 5; but differs in color, in 

 tenuity, and in the shape of the front of the pillar lip " 

 (Gray). 



Tliis unfigured species must be similar to. if not identical 

 with, P. bifrons Shuttl. 



5. P. BIFRONS (Shuttleworth). PI. 14, figs. 48, 49, 50, 51. 



Shell oblong-conic, rather thin, striate, a little shining. 

 Under a very thin, pale straw-colored epidermis it is whit- 

 ish, ornamented with a rather wide dilute blackish-purple 

 band below the periphery, and a darker columellar area. 

 Spire ovate-conic, rather long. "Whorls 7, rather flat or mod- 

 erately convex, the last about three-sevenths the total length ; 

 suture rather widely margined and very closely crenulate. 

 Columella narrow, thin, shortly truncatulate at base, in- 

 tensely and broadly bordered with black-purple within. 

 Aperture oblique, truncate-oblong; peristome simple, acute. 

 Length 47, diam. 22, apert. 20 mm. (Shuttl.). 



West Africa: Grand Bassam (Verreaux) ; near Bourbouri, 

 in banana plantations (Vignon). 



Perideris lifrons SH., Notitiae, i, p. 78, pi. 1; f. 1 (1856).- 

 PFR., Monogr., iv, 593 ; vi, 204. KGBELT, Conchyl. Cab., p. 

 43, pi. 13, f. 5-8. Achaiixa bifrons Sh., VIGNON, Bull. Soc. 

 Malac. France, v, p. 69. 



Differs from P. solimanus by the thinner and less glossy 

 subdiaphanous shell, more ovate spire, narrower, thin colu- 

 mella, which is not thickened and twisted. Over 40 speci- 

 mens were examined by Shuttleworth, who found them to 

 vary from more slender forms with flattened whorls, to those 

 more obese with the whorls a little convex. Unicolored shells, 

 without the dark bands, also occur. 



Figures 48, 49 are copied from Shuttleworth. Figs. 50, 

 51 represent a specimen in the Berlin Museum, sent by 

 Shuttleworth to Albers (after Kobelt). On pi. 7, fig. 39, I 

 have figured a specimen in coll. Acad. Nat. Sciences. These 

 are yellowish below the suture, and have a large, purple- 

 black basal area, which in some shells is divided, as in 

 Shuttleworth 's type, by a paler zone. In general contour 

 the species is excessively similar to P. reeveanus. 



