ZOOLOGY OF FERNANDO NORONHA. 485 



added at one eud ouly, thus producing a long narrow operculum- 

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

 rialism C. lividus, and C. rattus, 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 ajyical or suhapical. 



3. CoNus BAUcus, Hwass. 



Hah. Barbados {Ilns. Cuininy) ; St. Domingo and Gruadaloupe 

 (Kiister) ; Cuba and Martinique {jcVOrbljny). 



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 C. mamriiillaris, Green, C. castus, Eeeve 

 (not C. castas of AV^einkauff), C. archeti/pas, Crosse, and C. san- 

 guinolentus of Eeeve, 



C. Beevei, Kiener, placed by AVeinkautf f in the synonymy of 

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

 C. jpijjeratus, Dillwyn, not C. piperatus, Eeeve, which, as stated 

 by AVeinkautf, is the same as C. erythrodensis of Beck. 



4. Pleukotoma (Ceassispii!a) ruscEscENs, Gray. 

 1843. Plem'otoma fuscescens, Gray, Reeve, Con. Icon. fig. 125. 

 1845. Pleuiotoma nigiesceus, Gray, Reeve, I, c. fig. 235. 

 1845. Pleuvotoma paxillus. Reeve, tig. 285. 



1850. Plem-otoma sohda, C. B. Adams, Contrib. Conch, vol, i. p. 61, 



Sab. Cuba (d'Orbiyuy) ; Jamaica (C. £. Ad. for sollda); St. 

 Vincent {JReeve for nigrescens) . 



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

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

 mediate in size. 



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

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

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

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

 beyond a doubt the}' are distinct, PI. cuprea, Eeeve, 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. 



* Jouni. de Coiicli. 1874, pp. 333-359. 

 i' Conch. -Cub. p. ol2, uo. 63. 



