ZOOLOGY OF PEENANDO NORONHA. 



485 



added at one end only, thus producing a long narrow operculum' 

 MM. Cross and Marie * have also noticed, in respect of G. impe- 

 rlahs, C. lividtcs, and C. ratfus, that the nucleus of the operculum 

 is subapical, and doubtless it has a similar position in other 

 species. The description of the operculum therefore as usually 

 given in manuals and other works requires modification, and the 

 nucleus should be termed apical or sulapical. 



3. CoNus DAUcus, Hwass. 



Hah. Barbados (litis. Cuming) ; !St. Domingo and Gruadaloupe 

 (Xilster) ; Cuba and Martinique {cVOrligny). 



The single beach-rolled specimen has a very strongly marked 

 double zone of brown spots upon the middle of the body-whorl. 

 With this species I unite O. mammillaris, Grreen, C. castics, Reeve 

 (not C. castus of WeinkaufF), C. archetypus^ Crosse, and C. san- 

 guinolentus of Eeeve. 



C. Beevei, Kieuer, placed by AVeinkaufff in the synonymy of 

 this species, is quite a distinct shell, which I regard as the same as 

 C. piperatus, Dillwyn, not C. piperatus, Reeve, which, as stated 

 by A\^einkauff', is the same as C. crythrceensis of Beck. 



4. Pleukotoma (Ceassispiua) fuscescej^s, Orag. 

 1843. Pleuiotoma fuscescens. Gray, Reeve, Con. Icon. fig. 125. 

 1845. Plem-otoma nigrescens, Gray, Reeve, L c. fig. 235. 

 1845. Pleurotoma paxillus, Reeve, fig. 285. 



1850. Pleurotoma solida, C. B. Adams, Contrib. Conch, vol. i. p. 61. 



Hah. Cuba {d' Orhigng) ', Jamaica (C. £. Ad. for solida) ; St. 

 Vincent {Beeve for nigrescens). 



PI. nigrescens and PI. paxillus differ from the typical form of 

 the species in being very much smaller, PI. solida being inter- 

 mediate in size. 



In his ' Manual of Conchology ' (vol. vi. p. 193) Tryon states 

 that PI. nigrescens of C. B. Adams and PI. nigrescens of Gray 

 are the same species. Having types of the former received from 

 Adams and Grray's types also for comparison, I can state that 

 beyond a doubt they are distinct. PI. cuprea, Reeve, is rather 

 an unsatisfactory species at present, and I am rather inclined to 

 believe that, as suggested by Tryon, it will prove to belong to 

 this species also. 



* Journ. de Couch. 1874, pp. 333-351). 

 i" Conch. -Cab. p. 312, no. 63. 



