BULIMULUS-RHINUS. 75 



Key to species of Rhinus. 



I. Cuticular processes of two kinds : longer bristles in spaced spiral 

 rows, and numerous spirals between them bearing smaller 

 hairs. 



a. Nepionic whorls with the wrinkles much waved and in- 

 terrupted (pi. 13, fig. 25). 



b. Ovate-conic, rather solid, heterotrichus, p. 75. 

 b'. Ovate-globose, rather thin, longiseta, p. 77. 



velutinohispidus, p. 76. 



a'. Nepionic whorls very densely striolate longitudinally 

 (pi. 13, fig. 21) ; spire elevated, conic. 



b. Many spirals between the rows of bristles, which 



are about a millimeter apart, scobinatus, p. 77. 



b'. Fewer spirals between the rows of bristles, which 



are much nearer together, ciliatus, p. 78. 



II. Cuticle with a uniform close pile of subequal curved hairs; 



nepionic whorls densely zigzag striate. 



a. Columella with a projecting fold above; alt. 13-16 mill., 



pubescens, p. 81. 

 a'. Columella not folded ; alt. 22-25 mill., 



constrietus, p. 80 ; sarcochilus, p. 80. 

 B. koseritzi (p. 79) is not included in the above table. 



B. HETEROTRICHUS (Moricand). PI. 13, fig. 1 ; pi. 15, fig. 18. 



Shell narrowly umbilicate, ovate-conic, solid and strong or rather 

 thin ; chestnut-brown or light yellowish-brown, paler and yellowish 

 above, and with a narrow light girdle at the periphery, sometimes 

 having a spiral chestnut band within the umbilicus. Surface densely 

 spiralled with rows of short, curved and rather stiff hairlets, and 

 with widely spaced rows of separated stiff and much longer bristles, 

 usually in great part lost in adult shells, but leaving more or less 

 obvious scars (pi. 15, fig. 18). Spire straightly conic, the apex ob- 

 tuse, nepionic whorls densely and very finely waved and rugose. 

 Whorls about 65, but slightly convex, the last large and globose, 

 descending toward the aperture, a trifle contracted behind the peri- 

 stome. 



Aperture oblique, ronnd-ovate, purplish within ; peristome ex- 

 panded and narrowly reflexed, white; columellar margin dilated 



