NEOPETfLEUS. 179 



crossing each other"; spire conic, rather acute, suture slightly im- 

 pressed. Whorls 7*, rather flat, the last a little shorter than the 

 spire, rotund around the compressed umbilicus. 



Aperture vertical, sinuate-oval ; peristome simple, unexpanded, 

 acute, the columellar margin short, much dilated, angularly reflexed. 

 Columella somewhat folded above. Alt. 38, diam. (above aperture) 

 15* mill.; aperture 18 mill, long, 9 wide. (Pfr.). 



Andes of Prov. Caxamarca, Peru (W. Lobb). 



Buliinus decussatus RVE., P. Z. S., 1849, p. 99 ; Conch. Icon., pi. 

 72, f. 519. PFR., Monogr., iii, p. 431. 



" Singularly characterized by the bands of short brown streaks, 

 ranging obliquely in the direction opposed to the lines of growth." 



(Rve.). 



Var. BROWNII Pilsbry, n. v. PI. 32, figs. 40, 41 ; pi. 33, fig. 39. 



Shell slender and elongated, narrowly umbilicate, with slight 

 growth-wrinkles and no spiral striae. Whitish, with many narrow 

 tawny longitudinal stripes mingled with fewer of a deep chestnut 

 shade, the stripes bearing short oblique branches, and dots arranged 

 in several spiral series. Whorls 8 to 8j, the nepionic If smooth (in 

 five specimens seen), whitish, the following whorls but very slightly 

 convex, last whorl a trifle ascending in front or not so. 



Aperture decidedly less than half the total alt., long-ovate ; per- 

 istome hardly expanded, thin or somewhat thickened, the columellar 

 margin dilated ; columella bearing a strong fold deep within 



Alt. 41, diam. 15 ; alt. of aperture 17 mill. 



Alt. 36*, diam. 14; alt. of aperture 14* mill. 



Alt. 39*, diam. 15 ; alt. of aperture 16 mill. 



Peru, (A. D. Brown coll. in 'A. N. S. P.). 



More slender than N. decussatus, without spiral striation, and with 

 the aperture much smaller, contained nearly 2* times in the length 

 of the shell. The smoothness of the apex in the specimens seen may 

 be due to wear, but from the condition of the specimens I am dis- 

 posed to think that it is a case of degeneration of the sculpture. If 

 so, it is one of a very few Bulimulid species- in which this character 

 is really ambiguous as a generic criterion. 



One of the specimens before me is a faint creamy flesh tint, with 

 only faint, short markings below the suture and an inconspicuous 

 line of dots at the periphery, without other markings (pi. 33, fig. 

 39). 



