210 



LAND AND FRESII-WATER SHELLS OF N. A. [PART L 



3G2. 



Buliinulus xantusi, W. G. Binney. — Shell rimate, oblong-ovate, 

 clialky-wlnte, marked with numerous longitudinal wavy strife and de- 

 cussating minute revolving lines ; suture im- 

 pressed ; whirls five and a half, convex, the last 

 five-sevenths the length of the shell ; columella 

 arched ; aperture oblique, oval ; peristome simple, 

 sharp, its ends somewliat approaching, that of the 

 columella reflected ; the parietal wall of the aper- 

 ture covered with a light callus. Length 21 mill., 

 breadth 8 ; of aperture, length 10, breadth 6. 



Bulimus xantusi, W. G. Binney, Proc. Acad. 

 Nat. Sci. Philad. 1861, 331 (fig.). 

 Scutalus xantusi, Tbyon, Am. Jouru. Conch. Ill, 173, pi. xiv, f. 9 (1867). 



Cape San Lucas, Lower California. Mr. Xantus collected 

 four specimens agreeing in size and other characteristics. The 

 peculiar wavy stria3 and minute revolving lines are its especial 

 characteristics. 



Bulimulus xantusi. 



Subgenus PERONiEUS, Albers. 

 Shell perforated, oblong-turreted or subulate ; Avhite, generally- 

 streaked with horn-color; whirls 8-11, convex, the last equalling 

 about one-third the shell's length ; aperture oblong or oval, colu- 

 mella receding or obsoletely arcuated ; peristome expanded, not 

 thickened, its columellar margin dilated, patent. 



Bulimulus artemisia, W. G. Binn. — Shell rimate, subcylin- 

 drical, broadest at the second whirl, from which it gradually tapers 

 towards the apex, which is obtuse, its first whirl and a half 

 being bulbous, and marked by numerous strong longitudinal 

 ribs, white, nearly transparent, the longitudinal wrinkles of 

 growth scarcely roughening the almost smooth surface ; suture 

 distinct ; whirls eight, flattened, regularly and gradually in- 

 creasing, the last equalling one-half the whole length of the 

 shell ; aperture oblique, oval ; peristome simple, hardly thick- 

 ened, its terminations approached, and made continuous by a 

 white, upright callus, the columellar portion expanded.* 23 

 mill, long, 6 wide ; aperture 7 long. 



Bulimus artcmisia, W. 

 Philad. 1861, 331 (fig.). 



G. Binney, Proc. Acad. Nat. Sci. 



