460 Systematic Paleontology 



lated ; aperture rather narrow, obliquely lenticular ; labrum thin, sharp, 

 broadly arcuate ; labium smoothly and symmetrically concave, non-plicate ; 

 pillar flattened ; anterior canal short, broad, ill-defined. 



Dimensions (imperfect individual). — Altitude 34.9 mm., maximum 

 diameter 22.6 mm. 



This species is characterized by the subdued external sculpture, the 

 evanescence of the axials upon the final half turn, and the absence of 

 spirals upon the anterior and medial portions of the ultima. 



Occurrence.— Monmouth Formation. Brightseat, Prince George's 

 County. 



Collection. — Maryland Geological Survey. 



Pyrifusus cuneus Whitfield 



Pyrifusus cuneus "Whitfield, 1892, Mon. U. S. Geol. Survey, vol. xviii, p. 51, 



pi. iv, fig. 9-11. 

 Pyrifusus cuneus Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 24. 

 Pyrifusus mullicaensis Weller, 1907, Geol. Survey of New Jersey, Pal., vol. 



iv, p. 733, pi. lxxxv, figs. 12, 13 (ex parte). 



Description. — " Shell of medium size, short-fusiform, nearly twice as 

 long below as above the periphery of the last volution when viewed from in 

 front, and almost regularly sloping from that point to the pointed anterior 

 extremity, as seen in the cast; apical angle about 50° or 55°; volutions 

 about four; subangular on the periphery and marked by moderately dis- 

 tant but distinct vertical folds, which are obsolete on the lower third of the 

 volution, but increase in strength and distance with the increased growth 

 of the shell. Twelve of these folds can be counted on the body whorl of the 

 best preserved cast. Umbilical cavity in the cast, as left by the removal 

 of the columella, large and destitute of markings or folds of any kind; 

 aperture cuneate-elliptical, sharply pointed below and angular above ; sur- 

 face characters of the shell unknown. 



" This species is of about the size of P. erraticus, but differs someAvhat 

 in the form of the volutions and in the less elevation of the spire. The 

 volutions are more angular on the periphery and the angulation is com- 

 paratively higher than in that species, while the vertical folds are more 

 closely arranged. The lower portion of the volution is also not constricted 



