206 MUKEX. 



1st, Those in whieli the valves are arranged in pairs, and produce 



. a flattened figure, as Pedunculated Cirripedes, fig. 34 to 43 ; 

 2nd. Those in which they are arranged circularly, as Sessde 

 Cirripedes, the valves of which are of two kinds ; the oper- 

 cular, consisting of several valves, which close the aperture, 

 and the parietal, consisting of those which surround the 

 body of the animal in a circular form, fig. 14 to 33. 3rd. 

 Those in which they are arranged in a straight Hne, as Chiton, 

 fig. 227. 



MTJREX. Linn. (^ sharp rock.) Fam. Canalifera, Lam. sipho- 

 nostoma, Bl. — Descr. Turrited, ventricose, thick, with three or 

 more longitudinal, continuous, branched, spinose or fringed 

 varices ; spire prominent, acute ; aperture oval, terminating in 

 a posterior, partly closed canal, outer lip varicose, inner lip 

 smooth, laminar ; operculum horny, concentric, pointed.— 06*. 

 This genus contains some of the most exquisitely beautiful shells 

 in existence, the richness of their colouring, the ramifications of 

 their varices, would render most species the finest possible sub- 

 ject for the exercise of the painter's art in still life. The most 

 remarkable are the Kosebud Murex, with its pink-tipt fringes, 

 the Venus Comb, with its long rows of parallel spines • the 



. Ducal Murex, the Eoyal Murex, and many others, which are 

 much sought after by collectors. Murex may be distinguished 

 from Triton by the continuity of the varices, which follow each 

 other in a tortuous direction on the spire. The Eanellae have 

 only two rows of varices, and have a posterior as well as an 



. anterior canal ; while Murices have three or more varices, and 

 only one canal. The genus Typhis consists of several small 

 species resembling Murex in every respect, excepting that of 

 having a tubular opening on the upper part of the whorl between 

 each varix. See Tt:phis. The most beautiful Murices are 

 brought from tropical climates. PI. xvii. fig. 395, 396. The 

 genns Trophon, consisting of Mvirex Magellanicus, &c. may very 

 well be separated from the other types. M. Reeve's Mono- 

 graph of Murex, including the latter, contains nearly 200 

 species. 



