PLEUROTOMA.— Plate XII. 



Testa callositate in cornu brevi, quasi producto. 



Shell with the callosity produced, as it were, into a 



short horn. 



Pleurotomacornuta, Sowerby, Pro. Zool. Soc, 1833. 

 Hab. Panama and Bay of Caraccas (dredged from sandy 



mud at the depth of ten fathoms) ; Cuming. 

 The callosity and reflexion of the canal serve chiefly 

 to distinguish this species. 



Species 103. (Mus. Cuming.) 



Pledrotoma bicanalifera. Pleur. testd turritd, gracili, 

 fulvd ; anfractibus prope suturam concavis, lavibus, 

 infra longitudinaliter costellatis, costellis graniferis, 

 lineis elevatis, decussatis ; aperturd oblongd ; canali 

 labroque reflexis ; sinu lato, rotundato, quasi canalicu- 

 late. 



The two-canal Pleurotoma. Shell turrited, slender, 

 yellowish; whorls concave and smooth near the 

 suture, longitudinally ribbed below, ribs small, gra- 

 nular, and crossed with elevated lines; aperture 

 oblong; canal and lip reflected ; sinus broad, round- 

 ed, channeled as it were. 



Sowerby, Pro. Zool. Soc, 1833. 



Hab. Bay of Montija, Central America (dredged from 

 sandy mud at the depth of ten fathoms) ; Cuming. 

 I cannot very highly appreciate the specific title of this 



shell, because the technical value of the word " canal," 



as applied to the base of the shell, is in great measure 



injured when applied by analogy to a channeled sinus. 



Species 104. (Mus. Gray.) 



Pleurotoma callosa. Pleur . testd oblongo-turritd, fus- 

 cescente ; unfractibus transversim striatis, superne 

 depressis, infra longitudinaliter costellatis, costellis 

 numerosis, subobsoletis ; aperturd oblongd; labro co- 

 lumellari calloso ; canali brevissimo. 



The callous Pleurotoma. Shell oblong, turrited, 

 brownish ; whorls transversely striated, upper part 

 depressed, longitudinally ribbed below, ribs small, 

 numerous and somewhat obsolete ; aperture oblong; 

 columellar lip callous ; canal very short. 



Valenciennes MSS., Mus. Jardin des Plantes. 



Kiener, Icon., p. 50. pi. 18. f. 1. 



Hab. ? 



A solid heavy-looking shell, remarkable on account of 



the callous development of the columellar lip. 



Species 105. (Mus. Cuming.) 



Pleurotoma hexagona. Pleur. testd acuminato-pyra- 

 midali, rubido-fuscd; anfractibus hexagonis, subti- 

 lissinie striatis, tuberculosis, tuberculis per series sex 

 oblique ordinatis ; aperturd subovatd ; sinu lato ; ca- 

 nali breviusculo. 



The hexagonal Pleurotoma. Shell sharply pyrami- 

 dal, reddish brown ; whorls hexagonal, very finely 

 striated, tuberculated, tubercles ranging down the 

 shell in six oblique rows; aperture nearly oval; 

 sinus broad ; canal rather short. 



Sowerby, Pro. Zool. Soc, 1833. 



Hab. Guacomayo, Central America (dredged from sandy 

 mud at the depth of thirteen fathoms) ; Cuming. 

 I have only seen two specimens of this species, one 



collected by Mr. Cuming, the other by Captain Belcher. 



Species 106. (Mus. Cuming.) 



Pleurotoma clavulus. Pleur. testd subulatd, Icevi, albd, 

 nigro-variegatd ,inferne incrassatd; anfractibus piano - 

 convexis, suturis subindistinctis ; aperturd ovali ; la- 

 bro externa, incrassato, reflexo ; sinu subcirculari ; 

 canali brevissinw, paululum recurvo. 



The hob-nail Pleurotoma. Shell subulate, smooth, 

 white, variegated with black, lower part thickened ; 

 whorls flatly convex, sutures somewhat indistinct ; 

 aperture oval ; outer lip thickened, reflected ; sinus 

 nearly circular ; canal very short, a little recurved. 



Sowerby, Pro. Zool. Soc, 1833. 



Hab. Bay of Montija, Central America (found in sandy 

 mud at the depth of seventeen fathoms) ; Cuming. 



A very peculiar and distinct species, accurately repre- 

 sented in the accompanying plate. 



Species 107. (Mus. Stainforth.) 



Pleurotoma mystica. Pleur. testd abbreviato-fusiformi, 

 rubido-fuscd ; anfractibus superne concavis, striatis, 

 infra angulatis, tuberculis albis, connatis, ad unguium 

 acute carinatis ; anfractu ultimo inferne seriebus plu- 

 rimis nodulorum cingulato. 



The mystical Pleurotoma. Shell shortly fusiform, 

 reddish brown ; whorls concave and striated round 

 the upper part, angulated below, sharply keeled at 

 the ano-le with white connected tubercles; last whorl 

 encircled round the lower part with several rows of 

 nodules. 



Reeve, Pro. Zool. Soc, 1843. 



Hab. ? 



Chiefly distinguished by the white turrited keel. 



