292 DRYTO3US, SOUTH AMERICAN. 



by white lines, generally few in number, on the base. Spire long- 

 conic, rather acute ; whorls 7, a little convex, the last about three- 

 sevenths the total alt., rounded at base ; columella rather straight- 

 ened. Aperture a little oblique, truncate-oval ; peristome simple, 

 unexpanded, the right margin regularly arcuate, columellar margin 

 dilated above, reflexed. Alt. 31, diam. 15 ; alt. of aperture 15 mill. 



On the Mar anon River, northern Peru. 



Bulimus mexicanus LAM., An, s. Vert., vi, p. 123 (1822). VAL- 

 ENCIENNES, Rec. Obs. ZooL, etc., ii, p. 247, pi. 56, f. 1 (1833). DEL- 

 ESSERT, Rec. de Coquilles, pi. 27, f. 9 (1841). Not Bulimus mexi- 

 canus Reeve, 1848 ; cf. Crosse & Fischer, Moll. Terr. Mex., i, p. 541, 

 and v. Martens, Biol. Centr. Amer. Moll., p. 251. Helix (Cochlo- 

 gena) vittata Humboldt, FER.,Tabl. Syst., p. 54, no. 397 (110 descrip- 

 tion). 



Bulimus humboldtii REEVE, Conch. Icon., pi. 58, f. 391 (Jan., 

 1849). PFR., Monogr.,iii, p. 415; iv, 482; vi, 128 ; viii, 165. 



?" Bulimus (Mesembrinus) poecilus d'Orb. ?" LUBOMIRSKI, P. Z. 

 S., 1879, p. 725 (numerous color varieties described, from Chota, 

 Peru). 



It has long been recognized that the original B. mexicanus of 

 Lamarck (figured in Delessert's folio), is not a Mexican shell, but 

 identical with B. humboldtii of Reeve, the B. mexicanus of the lat- 

 ter author being a totally different thing. 



The typical form of mexicanus has three dark basal girdles inter- 

 rupted by fine white lines. Whether B. primularis deserves varie- 

 tal recognition or not I do not know, having seen no specimens. 



Var. primularis Reeve. (PI. 49, figs. 59, 60). 



Shell perforate, ovate-turrited, rather thin, nearly smooth ; yel- 

 lowish-white, ornamented with two wide black bands below the 

 middle and one interrupted median and another basal band of 

 chestnut. Spire long-conic, rather acute. Whorls 7, a little con- 

 vex, the last about three-sevenths the length, rotund at base ; col- 

 umella rather straightened. Aperture little oblique, truncate-oval ; 

 peristome simple, unexpanded, the right margin regularly arcuate, 

 columellar margin dilated above, vaultingly reflexed. Alt. 29, diam. 

 14 ; alt. of aperture 13 mill. (P/K). 



Chachapoyas, Peru (Lobb) ; Utcu bam ba River, north-eastern Peru 

 (Stiibel). 



