Zoological Society. 299 



Pleurotoma Harfordiana. Pleur. testd obeso-pyramidali ; an- 

 fractibus nigerrimis, in medio luteo-balteatis, convexis, transversim 

 subtilissime striatis, superne depressiusculis, serie unicd nodulorum 

 ornatis, infra noduloso-costatis ; aperturd breviusculd; sinu parvo, 

 rotundato. 

 Conch. Icon., Pleurotoma, pi. 11. f. 93. 



Pleurotoma Perronii. Pleur. testd fusiformi, turritd, laviusculd, 

 pallide luted ; anfractibus planis, superne leviter angulatis, ultimo 

 inferne coarctato, transversim lirato, liris regularibus, subdistan- 

 tibus ; sinu subcentrali ; canali subelongato, recto. 

 Conch. Icon., Pleurotoma, pi. 11. f. 94. 

 Murex Perron, Chemnitz, Conch., vol. x. pi. 164. f. 1573. 

 This interesting shell has been confounded by Lamarck with the 

 P. spirata. It differs from that species in being more erect and fu- 

 siform, in the sutures of the whorls being less deeply channeled, and 

 in the lower portion of the last whorl being crossed with about four 

 or five narrow, well-developed ridges. 



Pleurotoma pluteata. Pleur. testd fusiformi, gracili, fulvd; 

 anfractibus convexis, pluteo superne ornatis, medio nodulis albidis 

 catenulatis, infra subtilissime sulcatis ; sinu lato ; canali elongate 

 Conch. Icon., Pleurotoma, pi. 12. f. 101. 



The shelf which passes round the upper portion of the whorls is 

 not less characteristic of this species than the delicate chain of white 

 nodules which encompass the centre. 



Pleurotoma mystica. Pleur. testd abbreviato-fusiformi, rubido- 

 fuscd ; anfractibus superne concavis, striatis, infra angulatis, tu- 

 berculis albis, connatis, ad angulum acute carinatis ; anfractu 

 ultimo inferne nodulorum seriebus plurimis cingulato. 

 Conch. Icon., Pleurotoma, pi. 12. f. 107. 

 Chiefly distinguished by the white turreted keel. 

 Pleurotoma Philippinensis. Pleur. testd ovato -turritd, ventri- 

 cosd, subpellucidd, albidd; anfractibus sex septemve, longitudina- 

 liter costatis, costis eximiis, subcompressis, subdistantibus, nigro 

 aut fusco alboque varie pictd ; transversim liratis, liris minutis, 

 subcontiguis, numerosis ; columelld subtortuosd ; aperturd ovatd, 

 ampld ; canali brevissimo. 

 Conch. Icon., Pleurotoma, pi. 13. f. 109. 



Hab. Islands of Masbate and Luzon, Philippines (found under 

 stones at low water) ; Cuming. 



Pleurotoma Rissoides. Pleur. testd elongato-ovali, lavi, nitente, 

 semipellucidd, albicante , fulvo pallidissime nebulose strigatd ; an- 

 fractibus septem, tribus longitudinaliter plicatis ; apice rubello ; 

 columelld spiraliter tortuosd ; canali brevissimo, leviter recurvo ; 

 labro subincrassato, intus eximie denticulato, sinu parvo, distincto. 

 Conch. Icon., Pleurotoma, pi. 13. f. 111. 



This species reminds me somewhat of the Rissoa deformis ; the first 

 whorl or two are plaited as in that shell, the surface is moreover 

 smooth and shining, and they bear a general resemblance to each 

 other in size. The apex of this shell is peculiar in being pink, whilst 

 there is not the least indication of that colour in any other part. 



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