CERION, GROUP IX. 243 



This species, which has only been found fossil, is much heavier 

 than C. gubernatorium or C. eJeutherse. The lip resembles that of the 

 latter species, but is more strongly developed. It differs from both 

 in the strong parietal ridge. C. milleri is like C. ayassizi in the 

 raised parietal ridge and rather long parietal tooth, but it has a dif- 

 ferent and finer sculpture. 



There is a polymorphic recent species, varying from wholly costu- 

 late to quite smooth, having the strong parietal ledge of C. agassizi, 

 in the collection of the Academy (no. 76877). The specimens were 

 taken from among a lot of C. glans of unknown locality. The speci- 

 ,mens are bluish or livid white, with the lip less developed than in 

 agassizi. This race will probably be found to occur on some island 

 or key between New Providence and Eleuthera. 



C. MILLERI (Pfeiffer). PI. 36, figs. 44-49. 



Shell rimate, cylindric, terminating in an acutely conic, rather long 

 cone; solid and strong; dull white, rarely flesh-tinted, with sparse, 

 undulating, brownish-corneous streaks. Whorls 10^ to 12, nearly fiat, 

 the last well rounded below. Sculpture of fine, low stria on the last 

 whorl, or on its latter half, the rest oj the shell nearly smooth. Aperture 

 angularly ovate, white or slightly livid within ; peristome narrowly 

 refiexed, very much thickened, built forward ; parietal margin a 

 straight, raised callous ridge. Parietal lamella strong and moderately 

 long ; axial lamella inconspicuous. 



Length 38, diam. 12-13 mill. 



Length 31, diam. 13 mill. 



Length 28, diam. 12 mill. 



Bahamas : Duck Key, Exuma Group (W. W. Miller). 



Pupa milleri PFR., Malak. Bl. xiv, 1867, p. 129 ; Novit. Conch., 

 p. 365, pi. 84, f. 6-13 ; Monogr. vi, p. 289. ? Helix pentodon MENKE, 

 Zeitschr. f. Malak., 1846, p. 128 ; PFR., Monogr. 5, p. 185 ; Conchyl. 

 Cab., Helix, p. 198, pi. 100, f. 32-34. Of. v. MARTENS, Mai. Bl. 

 vi, 1859, p. 209. 



The very strong callous ledge across the parietal wall is character- 

 istic. The parietal lamella is strong and rather long, as in C. agassizi. 



The young shells of five whorls (fig. 47) have five small teeth. 

 Helix pendoton Menke was based upon a very young Cerion at this 

 stage, though probably not this species ; a fact first pointed out by 

 Prof. E. von Martens. 



