58 BULIMULUS-SOUTH AMERICAN. 



fleeted, lip simple. Dirty horn color. A thin horny shell with 

 the whorls somewhat rounded and rather deeply umbilicated (Reeve). 

 Central America (Cuming coll.) ; Campeche (A. Salle) ; and 

 Palizada (Morelet), Yucatan. 



Bulimus ignavus RVE., Conch. Icon., pi. 77, f. 562 (Aug., 1849). 

 B. dysoni var. B. PFR., Monogr., iii, p. 438. 



B. ignavus is considered by Pfeiffer, Crosse and Fischer and von 

 Martens a var. of dysoni characterized by the smaller, more fragile 

 shell, with the basal angle less conspicuous. Alt. 9, diam. 4 j- mill. 

 A specimen collected by Salle is figured by Crosse & Fischer (see 

 pi. 10, figs. 84, 85). I am disposed to think that ignavus is as dis- 

 tinct from dysoni as most of the middle American species of Lepto- 

 merus are from one another. 



Species of northwestern South America. 



Not different in general features from the forms of Central 

 America or eastern S. America. 



a. With minute spirals ; pale corneous-brownish or yellowish. 

 b. Large, alt. 22-32 mill. ; whorls 6!-7, cacticolus, erectus. 



bb. Small ; whorls 5! ; fine epidermal spirals, buenavistensis. 

 aa. Without spiral strise. 



b. Diameter less than half the alt. 



c. Alt. 20 mill.; aperture ! alt. ; whorls 6 ; pale reddish- 

 corneous, juvenilis. 

 cc. Alt. 21 mill. ; aperture nearly ! alt. ; whorls 7 ; rugulose- 

 striate ; pellucid straw-whitish, glandiniformis. 

 ccc. Long, rather solid, white; whorls 7 2-8; aperture con- 

 tained 2 times in alt., krebsianus. 

 cccc. Alt. 13! ; ovate, smooth, corneous ; whorls 6-7 ; aper- 

 ture f of alt., fontainii. 

 ccccc. Alt. 17!, aperture 8 mill, long; striatulate, pale cor- 

 neous, perforation minute ; whorls 6, molecillus. 

 bb. Diameter equal to or exceeding half the alt. 



c. Alt. 17, diam. 10, length aperture 10 mill.; globose- 

 conic, pale grayish-tawny ; whorls 4!, marmatensis. 

 cc. Alt. 12!, diam. 7!, aperture 6 mill. ; subhyaline; whorls 

 5, hyaloideus. 



ccc. Alt. 13, diam. 6!, aperture 6 mill. ; corneous-whitish, 

 smooth ; whorls 5!, ucayalensis. 



