MUREX. 71 



vex, ornamented with three or more continuous varices, which 

 are foliaceous, tubercular, or spinose ; aperture round or 

 ovate, ending in front in a contracted canal, long, straight 

 and tubular, or short and recurved, often partly closed. 



Byn. Purpura, Humph. Aranea, Perry. 



Ex. M. foliatus, Gmel'm, pi. 8, fig. 1. Operculum, M. 

 regius, Wood, fig. 1, a, 1, h. Shell, M. tribulus, Linnaus, 

 fig. 1, c. 



A remarkable peculiarity in this genus is the circum- 

 stance of the mantle-margin secreting varices on the com- 

 pletion of about a third of a whorl annually. In their 

 geographical distribution tropical America appears to har- 

 bour the greatest number ; they are, however, abundant also 

 in the Eastern Seas, the West Indies, and Africa. The 

 smaller cancellated species are usually from deep water, as 

 are those with wing-like varices {Pteronofus, Swains.) ; the 

 more highly-coloured species with frondose varices and 

 branching spines abound in rocky places near the coasts, and 

 the purpuriform species (Vitularla, Swains.) are principally 

 from coral reefs, under stones, and from crevices of rocks ; 

 the long-beaked spiny forms are usually dredged from toler- 

 ably deep water. 



Species of Murex. 



aduncospinosus, Beck. nigrispinosus, Reeve. 



brevispina, Lam. nodatus, Reeve. 



concinnus, Reeve. occa, Sow. 



duplicatus, Chem. plicatus, Sow. 



funiculatus, Reeve. pliciferus, Sow. 



hystrix, Mart. pulcher, A. Adams. 



messorius, Sow. rarispina, Lam. 



Mindanensis, Sow. rectirostris, Soiv. 



motacilla, Chem. recurvirostris, Brod. 



nigrescens, Sow. similis, Sow. 



