PSEUDOTROCHUS. 225 



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

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

 (Gray). 



This 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., Notitise, i, p. 78, pi. 1; f. 1 (1856). 

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

 43, pi. 13, f. 5-8.Achatina 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. 



