128 SYSTEMATIC PALEONTOLOGY 



Length, 11 mm.; width, 4 mm. 



Occurrence. — AqriA Foematiox. 1 mdle nonheast of Piscataway. 



Collection. — Maf^land Geological Survey. 



Genus .MANGILIA Risso. 



Subgenus PLEUROTOMELLA Verrill. 



MaXGILIA (PLEUROTOilELLA) BELLISTRIATA Clark. 



Plate XX, Figs. 13, 13a. 



Mangilia (Pleurotomella) hdlistriata Clark, 1895, .Johns Hopkins UdIv. Circ. toL xt, 



p. 4. 

 Mangilia (PleurotomeUa) hdlistriata Clark, 18^6, Bull. 141, U. S. Geol. Surrey, p. 65, 



pi. ix, Us. 5. 



Description. — •"'Shell small, subfusiform, with a rather short, pointed 

 spire, and about five whorls; body whorl large, somewhat inflated; earlier 

 whorls nearly flat; surface sculptured with numerous, alternating, larger 

 and smaller spiral threads, crossed by fine, wavy lines, and by irregu- 

 larly spaced, oblique ribs, about twenty in number on the body whorl; 

 ribs strongest at the shoulder, gradually disappearing both posteriorly 

 and anteriorly; behind the shoulder somewhat excavated; aperture nar- 

 row." Clark, 1896. 



There is a distinct fold on the columella, and the lines of growth are 

 very slightly citrved. 



Length, 27 mm. (restored); width. 13 mm. 



Occurrence. — Xaxjemoy Formatiox. Popes Creek. Aquia Forma- 

 Tiox. Potomac Creek. 



Collections. — Johns Hopkins ITniversity. Philadelphia Academy of 

 Xatural Sciences. 



Family CANCELLARIDAE. 



Genus CAN'CELLARIA Lamarck. 



Caxcellaria graciloides Aldrich. var. 



Plate XXI, Fig. 1. 



Cancellaria graciloides Aldrich, 1898, The Nautilus, vol. xi, p. 98. 

 6'a»<-e?/a>-i</ ^raci7oi<7^« Harris, 1899, BulL Amer. Pal., No. 11, pp. 28, 29, pi. iii, 

 figs. 10, 11. 



Description. — " Shell broadly fusiform, spire elevated, whorls 6-T, 



rounded, slightly shouldered, cancellated, first three smooth, on the 



