34 FOSSILS AND NON-MARINE MOLLUSKS 



This is a large, heavy, variable species with a peculiar thick duplex 

 sharp-edged lip. The shell varies from nearly smooth to rather finely and 

 closely rib-striate. An imperfectly preserved form resembling this species 

 was obtained from the narrow part of Eleuthera Island, opposite Savanna 

 Sound, at Station 18, and another on the same island about two miles north 

 of Governors Harbor, at Station 1. 



Cerion (Strophiops) rhyssum n. sp. 

 Plate XII, Figs. 4, 6. 



Fossil in the ffiolian rock of a small unnamed key south of Keids Cay, 

 Middle Bight, Andros Island, at Station 14. 



Shell large, heavy, solid, with a short parietal tooth, the axial tooth 

 absent or obsolete; axis a hollow cylinder with a small umbilical perforation 

 in the adult; whorls 10-11, the nepionic whorls at first smooth and polished, 

 then delicately axially striated; form cylindrical with a short apical cone, 

 sometimes much depressed; sculpture of the adult whorls of about IT rather 

 sharp, slightly oblique ribs, with wider interspaces, the basal Avhorl attenuated 

 and more finely wrinkled axially below; there is no basal cord or spiral stria- 

 tion; peristome slightly thickened and continuous. The color is, of course, 

 grayish white with traces of brown in the throat. Measurements of the two 

 most contrasted specimens, in millimeters are : 



Height. Max Diameter. Height of last whorl. 

 33 16.0 17 



26 17.5 16 



This species belongs to Maynard's section Pinguitia and seems most 

 closely related to C. dimidiatum Pfr., of which the short form is C. proteus 

 Gimdlach ; a Cuban species found at Gibara. 



Cerion (Strophiops) grayi Maynard. 



Strophia grayi Maynard, 1894, Contr. to Science, II, p. 138, figs. 42, 43. 

 Strophia ritcJiiei Maynard, 1894, op. cit. p. 135, fig. 41. 



Cerion (Strophiops) ritchiei, form grayi, Pilsbry, 1902, Man. Conch., XIV, p. 250, 

 pi. 39, figs. 93, 94, 98, 99. 



Small unnamed key south of Eeids Cay, Middle Bight, Andros Island, 

 at Station 14. Living at Highborn Cay, Maynard. 



This form is regarded by Dr. Pilsbry as a mutation of C. ritchiei which 

 may perhaps be the case; I have retained the name grayi, however, as the 

 specimens agree closely with tlie typical grayi while not so similar to the 



