﻿PROSOBRANCHIATA. 



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Pleurotoma claviculakis. Desk. 1832. Encyclop. Method. (Vers.), vol. iii, p. 796, 



No. 12. 



_ _ Desk. 1824-37. Coq. foss., &c, de Paris, vol. ii, p. 437, t. 69, 



f. 9, 10, and 15-18. 



— prisca. Desk. 1824-37. Idem, vol. ii, p. 436, t. 69, f. 1,2. 



— claviculare. Phil. 1846. Tert. foss. Magdeburg, p. 63, No. 113. 



— clavicularis. Bronn, 1848. Index Palseontol., p. 1002. 



— frisca. Bronn, 1848. Idem, p. 1008. 



— clavicularis. Rouault, 1848. Poss. du terr. eoc, &c, de Pau (Mem. Soc. 



Geol. de France, 2d ser., vol. iii, p. 481), No. 83. 



— prisca. Sow. 1850. Dixon's Geol., &c, of Sussex, p. 102, t. 7, fig. 24 ; 



and p. 119, t. 14, fig. 30. 



— — Bell. 1851. Foss. Nummul. du Comte de Nice (Mem. Soc. Geol. 



de France, 2d ser., vol. iv, p. 222), No. 86. 



— clavicularis. Bell. 1851. Idem, No. 87. 



— — D'Orb. 1852. Prod, de Paleontol., vol. iii, p. 359 : 25 e Etage ; 



Parisien, A, No. 404. 



— prisca. D'Orb. 1852. Idem, vol. iii, p. 416 ; 25 e Etage ; Parisien, B, No. 



1475. 



— clavicularis. N~yst. 1836. Coq. foss. de Hoesselt, &c, p. 31, No. 79. 



P. testa elongato-fusiformi, sub-glabrd : spird elatd, sub-conicd, acuminata -. anfractibus 

 ventricosis, poslice lineato-marginatis, ad basin transversim sulcatis, caterum Icevibus ; ultimo 

 anfractu in canali lato, indistincto, exeunle, ad extrcmitatem sub-profunde emarginato .- 

 aperturd oblong o -ov ali ; labro aliformi, tenui, acuto ; sinu lato, breviusculo, sub-trigono, 

 anticam in marginem collocato ; labio antice incrassato, rcjlexo ; columella leviter contortd, 

 antice cristatd. 



Shell elongated, fusiform, nearly smooth ; the spire almost conical, pointed, and 

 moderately elevated, being of equal length with the aperture. The whorls are slightly 

 ventricose ; when young, the whole surface is covered with moderately distant, 

 concentric, raised lines, in which state it resembles P. filosa (Lamk.) ; these lines, how- 

 ever, are lost on the fourth or fifth volution, and the whorls afterwards become 

 smooth and shining, except at the base and over the posterior margins, round the 

 sutural edges of which last run three or four fine threadlike, raised lines, occasionally 

 replaced by two or three shallow, obscure furrows ; the last whorl is nearly conical, 

 obscurely sulcated at the base and deeply notched at the extremity ; the anterior canal 

 is wide, very short, and indistinct. The aperture is narrow and of an oblong-oval form ; 

 the outer lip wing-shaped, projecting towards the front, thin and sharp on the edge, and 

 smooth within ; the sinus, which is in the very front of the margin, is wide, moderately 

 deep, somewhat triangular in form, and widely rounded at the extremity ; the inner 

 lip is much thickened, and is produced and bent outwards in front, giving an umbilicated 

 appearance to the columella, which is slightly twisted and prominently crested to- 

 wards the base. 



It appears to me to be impossible, satisfactorily, to separate P. clavicularis from 



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