54 



curve along tlie middle, incurved, rather sharp but stout, denticulate; 

 within: labium with a deposit of moderate thickness: columella some- 

 what produced. 



Mean divergence of the spire 50^; length of the spire .22 inch 

 total length .7 inch ; breadth .26 inch. 



Habitat — Bahamas. Fine specimens were collected on Turks Is. 

 by Dr. A. Barrett of Pittsfield, Mass. This beautiful shell is well 

 known in our collections, but I cannot learn that it has been described. 



Notes on the stnony,-my of certain marine shells. Bj C. B. Adams, 

 Jan. 1850. 



Pleurotoma plicata Ad. Bost. Journ. Nat. Hist. III. p. 318. pi. 3. 

 f. G. This name having been pre-occupied by Lamarck for a fossil 

 shell, my species may take the name of Pleurotoma plicosa. 



Pleui-otoma decussata Macgillivray Moll. Scot. p. 172. This spe- 

 cies, although perhaps figured in Brown's Illust. in 1827 with the 

 name Fusus decussatus, was first described in 1844, by the industri- 

 ous and learned author of one of the most complete local Fauna 

 Molluscorum which has ever appeared. This name was therefore 

 anticipated by Mr. Couthuoy for a Massachusetts shell in Feb. 1839. 

 The Scottish species may therefore take the name P. Macgilli- 



TBAYI. 



Pleurotoma violacea Hinds. Proc Zool. Soc. Lond. INIarch 28, 

 1843. The name of this species was anticipated by me in January 

 1842, for a species which inhabits Maine. Mr. Hinds' species^ may 

 therefore take the name of P. Peevii. 



Pleurotoma nigrescens Ad. Proc. Bost. Soc. Nat. Hist. Jan. 1, 

 1845, appears to be identical with P. nigrescens Gray (Ad. ?) Mss. 

 in Reeve Conch. Icon. pi. XXVI, No. 235, Nov. 1845. This spe- 

 cies, with P. ininor Ad. andP.fnscolineota Ad., was sent by me in 

 January 1845, to the British Museum, where they were seen by Sir 

 Robert Schomburgk. See his catalogue of West Indian shells in 

 Hist. Barbadoes, pp. 659—664. 



Pleurotoma fuscolineala Ad. Proc. Bost. Soc. Nat. Hist. Jan. 1 

 1845, very closely resembles, and perhaps is identical with P. scalpfa 

 Heeve Proc. Zook Soc. Loud. Jan. 27, 1846; but all my specimens 



