194 MUSCULAR IMPRESSIONS. 



smooth, laminar ; operculum horny, concentric, pointed. — Obs. 

 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 subject 

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

 able are the Rosebud Murex, with its pink-tipt fringes, the Venus 

 Comb, with its long rows of parallel spines ; the Ducal Murex, 

 the Royal 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 Ranellse have only two rows of varices, 

 and have a posterior as well as 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 Typhis. The most beautiful 

 Murices are brought from tropical climates. Fig. 395, 396. 



MURICANTHUS. Sw. A sub-genus of Murex, thus described : 

 "Varices numerous, foliated; spire short ; margin of the outer 

 lip with a prominent tooth near the base ; Radix. Sw. Zool. 111. 

 2nd series, pi. 113, Melanomathus. En. Meth. 418. f. 2." Sw. 

 p. 296. The latter of the two species quoted, however, does not 

 agree with the description, having no prominent tooth on the 

 margin of the outer lip. 



MURICATED. (Muricatus.) Having sharp points or prickles. 



MURICIDEA. Sw. A genus of "Muricinje," Sw. thus described, 

 *' Spire more produced, as long or longer than the body whorl ; 

 varices numerous ; no internal channel at the top of the aperture." 

 Sw. p. 297, and consisting of the following incongruous species, 

 "Lamellosa. Chem. f. 1823, 4. magellanica. En. M. 419. f. 4. 

 peruviana. lb. f. 5. senticosa, lb. f. 3. scaber. En. Meth. 419. f. 

 6. hexagona. lb. 418. f. 3. erinacea. Mart. f. 1026." Sw. p. 297. 



MUSCULAR IMPRESSIONS are the marks or areas formed on 

 the interior surface of shells by the muscular fibres which 

 attach the animals to them. Lamarck has divided his Conchifera 



