﻿PROSOBRANCHIATA. 3 1 7 



No. 241. Pleurotoma zonulata. F. E. Edwards. Tab. XXXII, fig. G, a, b. 



P. testa parvd, elongato-fusiformi, sub-turritd, omnino concentrice lineatd : anfractibus 

 depresso-convexis ; marginibus posticis sulcatis ; ultimo a nfractu sub-conico, in canali lato 

 brevi terminaio ; lineis concentricis crassiuscidis, per-elevatis, sub-distantibus : aperturd 

 ovali ; labro sub-recto, acuto, intiis plicalo ; sinu lato, prof undo, sub-trigono, ad humerum 

 collocato. 



Shell small, elongate, fusiform, and concentrically lined ; the spire is elevated, 

 exceeding the aperture in length, and somewhat turreted; thewhorls are flatlyconvex, and 

 furrowed round the posterior margins, the sutural edge of which is bordered by a single 

 prominent line ; the last whorl is nearly conical, and terminates, anteriorly, in a very 

 wide, short, but distinct and oblique, canal ; the concentric lines are rather thick, much 

 elevated, moderately distant, and nearly equal over the whole surface. The aperture 

 is of a widely ovate form ; the outer lip nearly straight, thin and sharp on the edge, and 

 plicated within ; the sinus is placed on the shoulder, and is very wide, deep, and sub- 

 trigonal in shape, with a much-rounded apex ; and the columella is slightly twisted. 



A very pretty and somewhat rare shell, the prominent and nearly equal transverse 

 lineation of which gives to it a screw-like appearance. It appears to be quite 

 distinct. 



Size. — Axis, 4-12ths of an inch; diameter, 1 -8th of an inch. 

 Localities. — Highcliff, Barton, Alum Bay (Stratum, No. 29, Prestw.) 



No. 242. Pleurotoma conoides. Solander* Tab. XXXIII, fig. 5, a, b. 



Murex conoides. Sol. 1/66. Brand., Foss. Hanton, p. 14, fig. 17- 

 — — Morr. 1854. Cat. Brit. Foss., p. 270. 

 Non. Pleurotoma conoidea. Nyst, 1843. Descr. des coq., &c, de Belg., p. 5 If), t. 40, fig. 9. 



P. testa utrinque sub-conicd, sub-turritd, longitudinaliter denticulato-plicatd, concentrice 

 lineatd: spird elevatd, acuminata ; anfractibus ad humeros acute angulatis, marginibus 

 posticis declivis, valde cavatis, ad suturam unicd lined, aliquando fasti giiformi, aliquando 



* The descriptions of this and the following two species, P. biconus and P. helicoides, have been, 

 accidentally, misplaced ; the species form part of the first section, in which the sinus is placed in the 

 margin of the whorls. 



