260 SYSTEMATIC PALEONTOLOGY 



Calliostoma wagneri Dall. 

 Plate LXI, Fig. 8. 



Calliostoma {eboreum Wagner var. ?) Wagneri Dall, 1893, Trans. Wagner Free Inst. 

 Sci., vol. iii, pt. ii, p. 399, pi. xxi, fig. 3. 



Description. — " Shell small^ rather depressed, with a rather large, 

 smooth nucleus and five subsequent whorls ; surface of the shell smooth ex- 

 cept for lines of growth; whorls at the periphery flattened, with two well- 

 separated keels, the upper the more prominent; the suture in the earlier 

 whorls is applied to the upper keel, but gradually recedes from it and 

 runs about midway between them ; immediately in front of the suture the 

 whorl shows a narrow, rounded ridge parallel with the suture; between 

 this ridge and the upper peripheral keel the surface of the whorl is exca- 

 vated or impressed to an extent varying in different specimens; base 

 smooth, umbilical region with a wrinkled callus, sometimes bounded by 

 one or two spiral grooves, but often without them; pillar short, thick, 

 with an obscure denticle; aperture subquadrate, outer lip simple, throat 

 not lirate." Dall, 1892. 



Height, 8.5 mm. ; diameter, 10 mm. 



Occurrence. — Choptank Formation. Greensboro, Governor Eun 

 (lower bed). 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Calliostoma aphelium Dall. 

 Plate LXI, Figs. 9, 10a, 10b, 11. 



Calliostoma aphelium Dall, 1892, Trans. Wagner Free lust. Sci., vol. iii, pt. ii, p. 

 400, pi. xxii, fig. 29. 



Description. — " Shell small, somewhat depressed, with five whorls ; 

 suture impressed, not channelled; upper surface of the whorls smooth 

 except for lines of growth and nearly invisible obsolete spiral markings, 

 somewhat flattened ; periphery prominent, almost carinated ; base slightly 

 rounded, without sculpture ; umbilicus represented by a deep imperforate 

 pit; umbilical fasciole strong, callous, irregularly vertically striated; 

 aperture subquadrate, outer lip simple, sharp; inner lip Ijroad, with a 

 callous knob upon it; body with a thin wash of callus." Dall, 1892. 



There is a subsutural row of white spots, and another row in the center 

 of the base. 



