274 DRYM.EUS, SOUTH AMERICAN. 



Dobrn and von Martens have fully discussed the geographic range 

 and synonymy of this species ; but the latter author erroneously 

 includes Bull in us culmineus Reeve (not Orb.). 



D. LEUCOMELAS (Albers). 



Shell compressed-umbilicate, oblong turrited, rather thin, striated, 

 white, or rarely pale buff, ornamented with blackish streaks, here 

 and there spotted with white. Spire lengthened-conic, rather acute. 

 Whorls 8, a little convex, the last forming nearly two-fifths of the 

 total length, somewhat compressed basally. Aperture slightly 

 oblique, narrow, acuminate-oval ; peristome simple, unexpanded ; 

 the columellar margin receding, dilated above, overhanging, con- 

 spicuous. Alt. 29, diam. scarcely 10 mill. ; aperture 12J mill, long, 



5* wide. (P/r.). 



On the Maranon River (Warscewicz). 



Bulimus leucomelas ALBERS, Malak. Bl., i, p. 219 (1854). PFR., 

 Monogr., iv, p. 488. 



D. VEXILLUM (Wood). PI. 48, fig. 33. 



Shell openly perforate, oblong- acuminate, thin, striate, shining; 

 whitish, with three equal blackish-brown encircling bands and a 

 fourth one around the perforation. Spire turrited, rather acute. 

 Whorls 8, slightly convex, the last two-fifths to three-sevenths the 

 total length. Aperture oblong-oval ; peristome thin, unexpanded, 

 acute; columellar margin subvertical, dilated. Alt. 32, diam. 12; 



length of aperture 14 mill. (Pfr.*). 



Tru.i'illo, Peru (Cuming). 



Helix vexillum WOOD, Index Testae., Suppl., pi. 8, f. 78a (1828). 

 -Ilidimulus vexillum BECK, Index Moll., p. 67. Bulimus vexillum 

 PFR., Monogr., ii, p. 205 ; iii, p. 427 ; iv, p. 490 ; vi, p. 136 ; viii, p. 

 171 (including jmlchellus, varians and rubellus). Bulinuspulchellus 

 BROD., P. Z. S., 1832, p. 106. SOWB., Conchol. Illustr., f. 17. Bul- 

 imus varians REEVE, C. Icon., pi. 18, f. 1 04 c. 



Var. VARIANS (Broderip). PI. 48, fig. 34. 



Shell openly perforate, oblong-acuminate; cream-white, closely 

 marked with ragged, irregular longitudinal streaks of blackish- 

 chestnut, the base with a light spiral band surrounding the col- 

 umella. Surface rather coarsely but sparsely and irregularly stri- 



