GASTEROPODA. 41 



1. Triton heptagonum. Broc. Tab. IV, fig, 8. 



MuREX UEPTAGONUS. BroccM. Conch, foss. Subapenn. vol. ii, p. 404, t. 9, fig. 2, a — b, 1815. 



T. Testa turritd, ovato-conicd subfusiformi; apice obtuso, anfractibus angnlatis, pris- 

 maticis, superne tumidis prope suturam depressis, plano-canaliculaiis ; stdcis transversis 

 crenatis ; varice solitaria marginali; aperturd ovatd ; labro intus dentato; canali aperto vix 

 recurvo. 



Shell turreted, subfusiform, with an obtuse apex ; volutions obtusely angulated ; 

 the upper part tumid and convex, with a flattened depression round the whorl near the 

 suture ; transversely ridged or sulcated, with distant longitudinal elevations ; aperture 

 ovate, and a thickened varix ; outer lip denticulated within; a narrow but open canal 

 of moderate length, slightly recurved. 



Axis, IJ; transverse dinmeter, Ij inch. 



Locality. Cor. Crag, Gedgrave. 



A single specimen of this beautifid shell is all I have as yet seen. It graces the 

 cabinet of Stephen Perry, Esq., of Rushmere, who has kindly intrusted me with it for 

 illustration. 



It differs slightly from the figure by Brocchi in having a shorter canal, and 

 a less number of ridges, and the outer lip is less angular than in the Italian spe- 

 cimen, but these differences are probably only local, and I have no doubt of its identity. 

 The volutions are slightly prismatic, with about seven faces. There are two varices in 

 this specimen, but it is probably an overgrown individual, and the last half volution 

 an effort of growth beyond its usual size ; the edges project beyond the margin of the 

 aperture, giving the varix a slightly fimbriated character, and the figure thus represents 

 it, but these hollow fimbriae are produced by erosion or decomposition of the shell at 

 that part. It has a small tooth-like projection upon the body whorl at the upper part 

 of the aperture, forming there a shallow canal, and a few folds upon the lower part of 

 the columella, which are probably only the elevated ridges of the exterior imperfectly 

 covered by the left lip. 



Pyrula,* Lam. 1801. 

 Sycotypus. Brown. 1756 (fide J. E. Gray). 

 FicrLA. Swamson. 1840. 

 Gen. Char. Shell thin, subovate, ventricose, fig, or pear-shaped, generally striated 

 or cancellated upon the exterior ; spire short and depressed, consisting of few volu- 

 tions ; aperture large and wide, terminating in a long, narrow, open canal ; columella 

 smooth, slightly tortuous ; outer lip sharp ; inner lip very thin and expanded. 



This genus still contains a large number of shells not possessing the above charac- 

 ters, being thick and hea\y, with a polished and sometimes a nodose exterior. Swainson 

 has justly separated these, and proposed the name of Ficula for the section we are now 

 considering, and Lamarck intended those species that are known in commerce by 



* Etym. The diminutive of Pyrum, a pear. 



