1919.] NATURAL SCIENCES OF PHILADELPHIA. 21 



Dimensions. — Altitude, 17.5 mm. Maximum diameter, 6.0 mm. 



Type Locai/^i/.— Smithfield, James River, Isle of Wight County, 

 Virginia. Yorktown Formation. 



Observations. — Drillia tricatenaria Conrad is more vigorously 

 sculptured than any of its congeners, even the closely related 

 Drillia pyrenoides Conrad. D. pyrenoides is, furthermore, a rela- 

 tively shorter, somewhat stouter shell than D. tricatenaria, with 

 a more rapidly tapering spire and a slightly shorter canal. The 

 axial costae of the former are much more nodose in character 

 than in the latter, while the spirals, both primary and secondary, 

 are fewer in number, more irregular and less prominent. Upon 

 the posterior fasciole, the spiral sculpture is often altogether obso- 

 lete, excepting for the sutural cord, which is always less prominent 

 than in D. tricatenaria. Members of this species appear under 

 such various names in the different collections that it has seemed 

 worth while to redescribe and figure the type kindly loaned for 

 the purpose by the Academy of Natural Sciences of Philadelphia. 



Distribution. — St. Mary\s Formation. Sycamore, Southampton 

 County, Virginia; 8 to 9 miles and 9 to 10 miles south of Green- 

 ville, Pitt County, North Carolina. Yorktown Formation. York- 

 town, York County; Smithfield, Isle of Wight County; Suffolk 

 and 1 mile northeast of Suffolk, Nansemond County, Virginia. 

 Duplin Formation. Natural Well, 1\ miles north of Magnolia, 

 Duplin County; Lake Waccamaw, Columbus County, North 

 Carolina. Muldrow's Place, 5 miles southeast of Mayesville, 

 Sumter County, South Carolina. 



Collections. — U. S. National Museum. Johns Hopkins Uni- 

 versity, Academy of Natural Sciences of Philadelphia. 



Drillia precursor new species. Plate I, fig. 1. 



General Characters. — Shell small, polished, rather slender, ob- 

 tusely tapering. Aperture less than half the entire altitude. 

 Whorls 1\ in all, flattened laterally, the profile of the spire feebly 

 crenulated, however, by the axial ribbing. Body whorl broadly 

 rounded, rather strongly constricted at the base. Volutions very 

 closely appressed, delimited by very fine and inconspicuous sutures. 



Protoconch. — Protoconch small, obtuse. Initial turn smooth and 

 almost entirely immersed in the succeeding volution. Sculpture 

 foreshadowed by the gradual introduction of a keel on the early 

 part of the second nuclear turn, — the spirals increasing in number 

 and prominence so that the close of the whorl is sculptured with 



