BULIMULUS-PLECTOSTYLUS. 



surface bearing spiral series of short bristles. Brown or cor- 

 neous shells with unicolored or few-banded coloration. Distri- 

 bution, Brazil. (Page . . .). 



Subgenus PLECTOSTYLUS Beck, 1837. 



Plectostylus BECK, Index Molluscorum, p. 58. GRAY, P. Z. S., 

 1847, p. 176, type B. peruvianus. Not Plectostylus Conrad, 1842, 

 see Proc. U. S. Nat. Mus., 1883, p. 184. 



Iraperforate, ovate or oblong, rather thin Bulimuli with the apex 

 small and conic, nepionic whorls minutely wave-striolate or vermic- 

 ulate-granose, the lip simple and unexpanded, columella with a long 

 fold or concave ; generally much speckled or streaked. Type B. 

 peruvianus. 



Almost exclusively a group of the Chilian sea-board, but at least 

 one species extends into Peru. The distribution is thus contrasted 

 with that of Scutalus, which is mainly confined to the Andean pla- 

 teau. 



Plectostylus is allied to Scutalus, but differs in the simpler, more 

 Succinea-like form, long aperture and unexpanded, thin outer lip. 

 The species may be tabulated as follows. 



Key to species of Plectostylus. 



A. Upper termination of the outer lip produced across the whorl as 

 far as the greatest ventral convexity (see pi. 6, f. 90) ; surface 

 spirally striated. 



a. Ventricose, the altitude less than double the diameter ; 

 boldly marked with "burnt " chestnut ; aperture very 

 oblique, coturnix. 



aa. Ventricose, altitude less than double the diameter; whit- 

 ish, densely spotted, tesselated, or irregularly variegated, 



broderipii, buschii. 



aaa. Slender, altitude about double the diameter; yellow, 

 with oblong spots in girdles, or streaks, 



variegatus, moestai. 



B. Upper termination of outer lip not produced, a profile view show- 

 ing the ventral convexity of body-whorl extending conspicu- 

 ously beyond it. 



