270 CERION, GROUP XII. 



C. FORDII Pilsbry and Vanatta. PI. 38, figs. 67, 68, 72. 



Shell cylindrical, the latter three whorls of equal diameter, those 

 earlier forming a rather short, obtuse cone. Whorls 10 to 10^, 

 earlier two white, smooth, the following finely striated, strias or rib- 

 lets evenly spaced though of variable closeness, in number 32 to 45 

 on the last or next to last whorl, not splitting or more numerous on 

 the base of the shell, which is rounded, not compressed ; umbilical 

 chink short, subperforate. Color : longitudinally mottled with 

 brown, ochre and snow-white ; sometimes uniform white. 



Aperture vertical or with the base somewhat advanced ; parietal 

 lamella about median, high, long and strong, extending backward 

 about four millimeters. Columellar fold very slight, situated high. 

 Peristome reflexed, its face much thickened ; light brown or whitish ; 

 parietal wall generally heavily calloused. 



Length 30, diam. of penult, whorl 12, alt. aperture 12^ mill. 



Length 27, diam of penult, whorl 12, alt. aperture 10^ mill. 



Length 28^, diam. of penult, whorl 11, alt. aperture 11 mill. 



Form submarmoratum P. & V. (PL 38, figs. 69, 70, 71.) Like 

 the type except that it is ribless, smooth with slight growth-wrinkles ; 

 sutures a little exserted and seam-like above. White, unicolored or 

 with irregular longitudinal dark fleshy brown stripes and sometimes 

 ochraceous stains. The first post-nepionic whorl of the cone is usu- 

 ally striated. Aperture typical. Bahamas. 



G.fordii P. & V., Proc. A. N. S., Phila., 1897, p. 365, figs. 1, 2, 

 and var. submarmoratum^ f. 3, 4 ; Nautilus, xii, p. 27, same figures 

 reprinted. 



Typical C. fordii exactly resembles externally a coarsely sculp- 

 tured form of G. datti from Inagua ; but it has the internal armature 

 of " Strophiops " or " Maynardia" It is a coarser, larger shell than 

 G. eximium of Cat Island and G. agrestinum of New Providence, 

 with far stronger development of peristome and teeth and more inter- 

 rupted strigation. G.fordii has not the raised ledge across the par- 

 ietal wall of G. glans varium, from New Providence, has stronger 

 peristome and teeth, and is larger. 



The pure white form of G. fordii resembles G. abacoense, but is less 

 stout in the average, has a liver-tinted mouth and lip, and the parie- 

 tal tooth is notably longer and stronger. 



Form submarmoratum is a larger shell than C. marmoratum, 

 stouter above, and with a much more developed parietal tooth. It 



