392 



TERRESTRIAL AIR-BREATHING MOLLUSKS. 



a light-colored aperture, a shorter and more pyramidal spire, and by the want 

 of the highly developed tooth-like fold upon the columella. It is of a dead 

 white color, not variegated with brown blotches. The aperture is shorter and 

 wider, and there is no strong internal white thickening to the peritreme. Like 

 all the species of the group it has a highly polished, very light waxen apex. 

 There are sometimes light delicate waxen vittaR upon the first two whorls. 



No description of this species was given by Dr. Binney, nor was it figured 

 unless in PI. LI. Fig. 2, as B. dealbatus, var. On p. 278 of Vol. II. Dr. Gould 

 erroneously refers to it PI. LI. b. 



There is a great difference in the comparative globoseness of the various 

 specimens. 



The shell figured as a variety of B. Schiedeanus with a dark-colored aper- 

 ture in the fourth volume of the Terrestrial Mollusks (PI. LXXX. Fig. 15) is 

 rather a specimen of Bui. alternalus, in which the columellar fold is not as 

 strongly developed as usual. Fig. 8 of the same plate I describe below as v ari- 

 ety Mooreanus. 



Lingual membrane as in dealbatus. Jaw with 13 ribs. 



Variety Mooreanus. 



Shell perforated, ovate-conic, thin, white, with a dark lead-colored apex, and 



below the middle of the body-whorl of a light coffee- 

 Fig. 277. ... ? 



color ; smooth, with microscopic revolving lines ; 



whorls 7, convex, the last equalling about two thirds 

 the shell's length ; aperture ovate, light within ; colu- 

 mella straight; peristoriie acute, very thin, with 

 an internal delicate white rim, its margins uncon- 

 nected with callus, that of the columella broad, 

 white, slightly reflected. Length, 25 mill. ; breadth, 

 12 mill. 



Bulimus Schiedeanus, var., W. G. Binney, Terr. Moll., IV. 129, PI. LXXX. 



Fig. 8. 

 Bulimus Mooreanus, Pfeiffer, Mon., VI. 143 (1868). 



Found in large numbers in Washington and DeWitt Counties, Texas, by 

 Fig. 279. Dr. F. W. Moore, and at Leon by Fig 278 



Lieutenant Beale. 



It is a more fragile, highly polished 

 shell than B. Schiedeanus, and is pe- 

 culiar in having the dark apex and 

 the body-whorl light coffee-colored 

 below the upper margin of the aper- 

 ture. In one case only have I ob- 

 served the whole shell of this color; it was then 

 of a darker hue. There is an extremely light, 

 transparent callus on the parietal wall of the aperture. 



B. Mooreanus. 



B. Mooreanus. 



B. Mooreanus. 



