GASTEROPODA. 39 



Murex, Linn. 1767. 



Chicoreus. Mont/. 1810. 

 Triton. Flem. 1828. 

 Piiyllonotus. Swains. 1840. 

 Pteronotus. 

 muricidea. 



Gen. Char. Shell turreted, elongato-ovate, or fusiform; generally ventricose, 

 thick, and strong ; externally rugose, with three or more longitudinally branched, 

 spinous, fringed, or reflected fimbriae, more or less elevated, foliaceous, or tuber- 

 culous ; spire prominent and acute ; aperture ovate, terminating at the base in a 

 partly closed canal ; operculum corneous, concentrically formed and pointed. 



The shells of this genus have three or more divisions of the volution, formed by 

 an extended or fimbriated margin of the outer lip, at different periods of growth, 

 by which means the shell is elegantly ornamented externally ; and among the 

 recent portion of the genus are some of Nature's most beautiful productions. It 

 differs from Ranella, which has only a bipartite division of the whorl, and in Triton 

 the varices are more irregular, and not fimbriated. This genus is found in the 

 Oolite, and twenty species are enumerated as belonging to the Paris basin. M. 

 Michelotti mentions forty-four from the Subapennine beds. Only two species have 

 as yet been found in the Crag, and those are by no means numerous in individuals. 



1. Murex erinaceus, Linn. 



Murex erinaceus. Linn. Syst. Nat. p. 1216. 



— Pennant. Brit. Zool. iv, t. 76, fig. 95, 1776. 



— Brocchi. Conch, foss. Subap. p. 391, pi. 7, fig. 11, 1814. 



— Bujardin. Mem. de la Soc. Geol. de France, 1837, p. 295. 



— S. Wood. Catalogue 1842. 

 Triton erinaceus. Flem. Brit. An. p. 356, 1828. 



M. Testa ovato-fusiformi, transversim sulcato-ruc/osd, quadrifariam ad septifaridm 

 varicosd ; varicibus clevatis ; aperturd ovatd ; canali clauso recurvd. 



Shell subfusiform, ovate ; roughly sulcated transversely with from four to seven 

 rather obtuse varices ; aperture ovate, with a slightly recurved canal, which is out- 

 wardly closed in the adult state. 



Locality. Mam. Crag, Bramerton. Recent, Britain. 



One specimen of these species was found some years since by Mr. J. Wigham, of 

 Norwich, and sent to Mr. Lyell, with whom I examined it, and we were both satis- 

 fied of its identity with the well-known recent shell. Upon application to the 

 owner of the specimen for the privilege of having it figured, he informed me it had 

 been sent to Mr. Green, of Bacton, for the purpose of publication, and unfortunately 

 lost. 



