SIMPSON — CONTRIBUTIONS TO THE MOLLUSCA OF FLORIDA. 55 



"Shell polished, shining, with (including the nucleus) six and a half 

 whorls; nucleus madder-brown, smooth, rather large, blunt, with one 

 and a half turns; remainder transversely ribbed with 8-10 smooth, 

 rounded, nearly straight, stout ribs, extending from suture to suture, 

 which begin with the end of the nuclear part, and fail at the last third 

 of the last whorl, which is marked only by silky fine incremental striae; 

 the spaces between the ribs are equal to or somewhat less than the 

 ribs in width; longitudinal sculpture none, or only occasional extremely 

 faint microscopic lines; whorls not inflated; color, rosy pellucid white, 

 banded in front of the suture with rosy brown, fainter on the ribs, and, 

 in the specimen described, extending forward nearly to the periphery 

 of the earlier whorls ; the base of the last whorl similarly tinged ; the last 

 somewhat varicose rib and the outer thickened lip whitish ; aperture and 

 canal very short and wide, and notch deep and large, rounded, leaving 

 no fasciole, the outer lip lightly thickened, arched forward, a slight 

 callus on the columella; interior not lirate in the specimen described. 



"Lon. 5.75 mm. ; last whorl equal to half the total length; maximum 

 diameter of shell, 2.1 mm. 



"Two specimens of this extremely pretty little shell were obtained at 

 Tampa Bay by Mr. Simpson. It differs from any known form from 

 that region heretofore, and in the form of its aperture and notch re- 

 calls some of the west coast Drillias, but, owing to the absence of a 

 fasciole in front of the suture, can hardly be referred to that section of 

 the Pleurotomidre. One specimen is in the collection of the National 

 Museum, No. 61,040." 



The only two specimens obtained of this species were dredged in 

 about five fathoms. 



Pleurotoma monilifera Sby. Tortugas. 



Pleurotoma auberiana D'Orb. ? Tortugas. 



Pleurotoma nigerrima Dall. Tortugas. 



Pleurotoma t/iea Dall. Sarasota Bay. 



Pleurotoma fuscescens Gray. Sannibel Island. 



Pleurotoma leucocyma Dall. Key West. 



Pleurotoma flavescens Reeve. Tortugas. 



Pleurotoma quadrata Reeve. Tortugas. 



Mangilia stcllata Stearns. Long Key. 



Mangilia balteata Reeve. Tortugas. 



Mangilia balteata, var. Tortugas. 



*Clathurella jewettii C. B. Ad. Cedar Keys, Hemphill. 



*Clat//urella jewettii Stearns. Cedar Keys, Hemphill. 



The Pleurotomidas are in great confusion, and but little is accurately 

 known concerning the species. I have used the generic name Pleuro- 

 toma for the species sometimes classed under the generic name of 

 Drillia. 



Conns floridanus Gabb. Cape Sable and northward. 



