PROCEEDINGS OF THE NATIONAL ilUSEUM. 37 



The name curvilineata, by a typograpliical error, appears in Meek's 

 Miocene check list for T. eurmliraia, Conrad, a species from St. Mary's 

 River, Maryland; bnt it has never been applied to any described spe- 

 cies from oar Tertiary heretofore. The species has something in com- 

 mon with the more rngose specimens of T. {Hastula) simplex, Conrad, 

 but is perfectly distinct. 



TEREBRA (ACUS) CURVILIRATA, Conrad. 

 Tercbra curi-ilirata, Conkad, Proc. Acad. Nat. Sci. Phila., I, p. 327, 1843. 



This is an old species of Conrad's, which does not appear to have 

 been figured. The shell is small, not exceeding 30 mm. in length, with 

 rather swollen whorls constricted narrowly above, much as in Pleuro- 

 toma of the section Cijmatosyrinx. The ribs are about 12 to the whorl 

 and most prominent at the periphery; their posterior ends are con- 

 stricted off near the suture without any distinct groove or incised line; 

 they are strongly curved in front of the constriction; the surface has 

 extremely fiiint, obsolete spiral sculpture, only visible with the aid of a 

 lens; the pillar thin, simple, and twisted, rather short; the nucleus is 

 conical, of four smooth whorls like a small, very much elevated Callios- 

 toma, except that the whorls are rounded. A specimen 15 mm. long 

 had ten whorls, exclusive of the nucleus, and a maximum diameter 

 of 4.75 mm. 



Hdhitaf. — Miocene of St. Mary's River, Maryland. Types in Acad- 

 emy of ISTatural Sciences; specimens in U. S. I^Tational Museum (Nos. 

 10G950, 106957). 



TEREBRA (ACUS) SINCERA, new species. 



Shell small, thin, acute-conic, flat-whorled, with feeble sculpture; 

 whorls ten, without the nucleus; anterior half of the whorls, with fine, 

 feeble, spiral threading overrunning the ribs, posterior half without 

 spirals, but divided into two equal parts by a spiral groove visible 

 between the ribs; transverse sculpture of fine, low, even, narrow, 

 arched riblets, with wider interspaces, extending clear across the whorls ; 

 suture distinct, sutural band obscure, not swollen ; aperture longer than 

 wide, outer lip thin, arched in harmony with the riT)s; pillar short, 

 smooth, or faintly excavated; canal recurved, not contracted. Longi- 

 tude, 22; maximum diameter, 5 mm. 



Habitat. — Miocene of St. Mary's River. Maryland. 



Ty2)es.—:^o. 11873 «, U. S. N. M. 



This species is quite distinct from the others of the St. Mary's hori- 

 zon, and when perfect is easily recognized. When superficially eroded 

 the ribs are more prominent, as is the succeeding whorl at the suture, 

 and the whorls may have a slightly turrited appearance. 



