252 CERION, GROUP XI. 



Subsp. VANNOSTRANDI Pilsbry and Vanatta. PI. 39, fig. 2. 



Large, solid and white ; smooth except for some irregular folds on 

 the latter portion of the last whorl. Whorls nearly 12. Aperture 

 small, dark brown within, the peristome not expanded, built forward 

 and rugose outside; teeth very strong. Length 40^, diam. 15-J } 

 longest axis of aperture 13 mill. Habitat unknown. 



The only smooth member of the C. glans group known. 



C. EBURNEUM (Maynard). PI. 39, fig. 3. 



Shell with a compressed umbilical chink, cylindric, solid, white ; 

 regularly and rather closely ribbed throughout, the ribs as wide as 

 their intervals, about 29 on the penultimate whorl. Whorls 10-10^, 

 but slightly convex, the last with a straight umbilical chink and 

 moderately wide umbilical area. Aperture angularly ovate, brown 

 inside ; peristome very narrowly recurved, its face thickened, the 

 margins connected by a strong straight parietal ledge. Parietal 

 lamella strong, more or less duplicate, or buttressed on the left side ; 

 axial lamella small but distinct, a low accessory tubercle sometimes 

 appearing above it. 



Length 321, diam. 12 mill. 



Length 28|, diam. 11J mill. (type). 



Length 25, diam. 11^ mill. 



Bahamas: U Key, one of the Allen's Harbor group, north of 

 Highborn Key, on the low, sandy southern portion (Maynard). 



Strophia eburnia MAYN., Contrib. to Science, ii, p. 144, f. 45 

 (December, 1894) S. elongata MAYN., t. c., p. 148, f. 46. 



This form is closely related to C. ritchiei of Highborn Key. It is 

 somewhat more slender and more closely ribbed, with the lip some- 

 what thicker. 



U Key is a small key north of Highborn Key, shaped like the let- 

 ter U, about a quarter of a mile long, and nowhere over a hundred 

 yards from shore to shore. Upon the southern end of this key, 

 among scattered palms, Mr. Maynard found hundreds of dead, 

 bleached shells of this species! On the little hill on the eastern 

 boi-der of the low, sandy tract, twelve living specimens were collected 

 from some low bushes. The form is evidently almost extinct, its 

 area having been invaded by wind-blown sand, according to Mr. 

 Maynard. 



