DRYM^EUS, SOUTH AMERICAN. 225 



last perceptibly compressed above, very convex at the periphery, 

 slightly ascending behind the lip. 



Aperture ovate, vertical, half the length of shell, white or streaked 

 with reddish within ; peristome thin, white, the outer lip slightly 

 expanded above, becoming broadly so below ; columella nearly 

 straight, its margin very broadly dilated above, making an angle or 

 even slightly channeled at its junction with the body-whorl. Alt. 

 26, diam. 12 J; alt. of aperture 12i-13 mill. 



Moyobamba, eastern Peru (Yates). 



Bulimus protractus PFR., P. Z. S., 1855, p. 94, pi. 31, f. 1 ; Novit. 

 Conch., i, p. 66, pi. 18, f. 13, 14 ; Monogr., iv, p. 389 ; vi,p. 35. B. 

 prostratus SCHAUFUS in Patel Catal., p. 81 . 



The black apex, rather coarse striation and peculiar columellar 

 lip are its more prominent features, the latter being formed as in 

 other members of this group of species, most of which are stouter 

 shells than protractus. 



Pfeiffer mentions a variety which is smaller, the last whorl sub- 

 angular, right margin of the peristome slightly curved. 



D. NIGROGULARIS (Dohrn). PI. 42, figs. 56, 57, 58, 59. 



Shell narrowly rimate or perforate, oblong-acuminate, spirally 

 striatulate, a little wrinkled obliquely, shining, thin, semipellucid, 

 pale yellowish or buff, uniform or streaked with chestnut; spire 

 lengthened, the apex decussated, rather acute; suture simple. 

 Whorls 7, a little convex, the last whorl about as long as the spire, 

 somewhat compressed at base. Aperture little oblique, truncate- 

 oblong, subeffuse, colored within like the outside, the parietal wall 

 black ; peristome citron tinted, thin, expanded, the margins ap- 

 proaching, joined by a thin callus, right margin moderately arcuate, 

 basal margin somewhat receding, columellar margin vertical, tri- 

 angularly dilated above. Alt. 29-34, diam. 13-15 mill, aperture 

 16-17 mill, long, 10-12 wide (Dohrn'). 



Juraty, prov. Para, on the right bank of the Amazon River. 



Otostomus nigrogularis DOHRN, Jahrb. D. Mai. Gesellsch., ix, 

 1882, p. 107, pi. 3, f. 10-13. 



Belongs to the numerous group of very similar species like B. 



geometricus Pfr., B. xanthostomus Reeve (not Orb.), etc., but known 



from all of them by the black-calloused parietal wall. The variations 



in contour consist in the greater or less slenderness of the spire, and 



15 



