GASTEROPODA. 41 



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



Murex heptagonus. Brocchi. Conch, foss. Subapenn. vol. ii, p. 404, t. 9, fig. 2, a — b, 1815. 

 T. Testa turrltd, ovato-conicd subfusiformi : apice obtuso, anfractibus angulatis, pris- 

 maticis, superne tumidis prope suturam depressis, plano-canallcidatis ; sulcus transversis 

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

 vix recurvo. 



Shell turreted, subf usiform, with an obtuse apes ; 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, If ; transverse diameter, l^inch. 



Locality. Cor. Crag, Gedgrave. 



A single specimen of this beautiful 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 speci- 

 men, 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 volu- 

 tion 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 fimbrias 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). 

 Ficula. Swainson. 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 volutions ; 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 

 characters, being thick and heavy, 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 



* Etym. The diminutive of Pyrum, a pear. 



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