26 PROCEEDINGS OF THE ACADEMY OF [Feb., 



anterior fascicle adorned with about 4 rounded, elevated, close-set 

 cords. 



Aperture. — Aperture very narrow, somewhat crescentic. Pos- 

 terior commissure well rounded. Outer lip arcuate, smooth within. 

 Columella concave, bearing 3 folds, of which the two posterior 

 are the strongest. Anterior canal short, recurved, slightly emar- 

 ginate. 



Dimensions. — Altitude, 8.0 mm. Maximum diameter, 2.5 mm. 



Type Locality. — Muldrow's Place, 5 miles southeast of Mayes- 

 ville, Sumter County, South Carolina. Duplin Formation. 



Observations. — The species is characterized not only by the spiral 

 furrow but also by the slender, tabulated outline of the whorls. 

 The type has been compared with the foi'm from which Ball's 

 description was made and there is no doubt of their identity. 

 The young of the species are stout little cones with well devel- 

 oped sculpture and an angular whorl. 



Distribution. — Yorktown Formation. Drainage ditch 1 mile 

 northeast of Suffolk, Nansemong County, Virginia. The young 

 individual collected at this locality is referred rather doubtfully 

 to this species. 



Duplin Formation. — Muldrow's Place, 5 miles southeast of 

 Mayesville, Sumter County, South Carolina. Caloosahatchie For- 

 mation. Caloosahatchie River, Florida. 



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

 versity. Academy of Natural Sciences of Philadelphia. 



Mitromorpha mitrodita new species. Plate I, flg. 7. 



General Characters. — Shell very small, fusiform, the greatest 

 diameter falling at or just anterior to the median line of the shell. 

 Aperture nearly half the total altitude. Whorls of conch 4^ in 

 number, regularly increasing in diameter, those of the spire some- 

 what trapezoidal in outline, the body broadly arcuate. Sutures 

 inconspicuous, undulated by the costse of the preceding whorl. 



Protoconch. — Protoconch twice coiled. Initial turn minute, in- 

 flated, immersed only at the tip. Succeeding volution relatively 

 high, broadly convex. Opening of conch indicated by the abrupt 

 appearance of the axial and spiral ornamentation. 



Sculpture. — Axial sculpture less conspicuous than the spiral; 

 costse confined largely to the earlier whorls and tending to become 

 obsolete on the ultima and penulta, 9 to 10 in number, low, rounded, 

 and undulating, continuous from suture to suture but most promi- 



