BULIMULTJS. 



191 



Jaw arcuate, roughened by stout ribs, its concave margin 

 crenated. 



Bulimus spirifer, Gabb. — Shell rimately perforated, subfusi- 

 formly-oblong, thin, with delicate striie of increase, in some places cut by 

 fine revolving lines, pellucid, of a dead white color, or 

 horn-color; spire turreted conic, apex acute; whirls six, 

 convex, the last equalling two-thirds of the shell's 

 length ; aperture truncate-ovate ; peristome white, shin- 

 ing, broadly expanded, reflected, acute, cohimellar portion 

 very broad, widely reflected over the rimation, bearing 

 far within upon its centre an upright, stout, twisted fold, 

 ends approaching, connected by a shining white callus. 

 Length 31, diam. 11 ; aperture 15 long, 11 mill. wide. 



Bulimus spirifer, Gabb, Am. Journ. Conch. Ill, 236, pi. 

 xvi, f. 5 (1867). 



Bulimus spirifer. 



From San Antonio to San Borja, Lower Cali- 

 fornia. Very common (Gabb). 



The description and figure are drawn from an authentic 

 specimen. 



Jaw like that of Orthalicus,^ in about nineteen separate plates, 

 whose overlapping seems to produce narrow longitudinal costae. 



BULIMITLIIS, Leach. 



Shell oblong, aperture longitudinal, edentulate, peristome 

 thin, mai'gins unequal ; columella integral. 



Jaw arcuate, with stout anterior ribs.^ 



Lingual membrane (of B. dealbatus) broad, central teeth 

 tricuspid, the median cusp very long ; laterals bicuspid. 



Fig. 333. 



Lingual membrane of Bulimvlus dealbatus. 



' This does not agree with the generic description. 



^ Martens and Albers say "composite ;" but I have not found it so with 

 all those I have examined. 



