BULIMULL'S. 



203 



in the second edition of Chemnitz, and from authentic speciiucns 

 in my collection. 



Buliinus marise. — Shell perforate, ovate pyramidal, striatulate, shining, 

 white, varied irregularly with diaphanous bands and spaced blotches ; 

 whirls six and a half, convex, joined by a deep suture, the last a little 

 shorter than the spire ; columella somewhat constricted, strongly tubercu- 

 late above ; aperture oblongoval, smoky within ; peristome whitely labiate 

 within, broadly expanded, its columellar margin reflexed, patent. Length 

 30, diam.l2; of aperture, length 12, interior breadth 7 mill. Hah. — . {Albers.) 



Fig. 349 represents a common form of Bulimus Fig. 349. 

 inariag.^ 



Dr. Pfeififer's description of B. marise is as ^ \|> 



follows : — 



Shell narrowly umbilicated, oblong-conic, solid, rather 

 smooth, white, often marked with spots and obsolete 

 blotches of horn-color ; spire conic, acute ; whirls six and 

 a half, rather convex, the last aboiit as long as the spire, 

 hardly attenuated at base : columella with a small denti- 

 form fold ; aperture scarcely oblique, acuminately-oblong, 

 brownish within ; peristome straight, its right margin 

 somewhat arclied, its columellar margin broadened above, 

 spreading. Length 33, diam. 14-15 mill, ; of aperture, 

 length 16-17, breadth 7 J. 



One of the uniformly white forms of the species 

 is figured in Fig. 350, and two of the same from 

 the table-land west of Fort Clark, figured in Fig. 

 348, show the variation in breadth of which the 

 species is capable. 



There are about seventy-six rows of teeth on the BnHmnhts 

 lingual membrane of B. alternatus, each consisting 

 of 75 (37 — 1 — 37) teeth. Central teeth long, simple, bluntly 

 pointed, the laterals bicuspid, modified as they pass off laterally. 



Fig. 351. 



350. 



Lingual dentition of Bulimulus altematua. 



' The figure being in outline is unshaded in the aperture, which in the 

 original is dark brown. 



