MONOGRAPH OF THE GENUS 



MUREX, Linnceus. 



Generic Character. — Testa canalifera spiraliter plus mi- 

 nusve lirata aut striata, varicosa ; varicibus utroque anfractu 

 tribus aut plurimis, ad laterem sinistrum canalis plerumque 

 exfoliatis, canali lamina discoidea aut elongata, plana, aut 

 urnbilicata versus marginem aperturae externiun extensa par- 

 tim penitusve tecto. Operculum corneum, nucleo laterali 

 aut terminali. — It is difficult to define this genus, so as to 

 include all the species that do, and to exclude all that do not, 

 belong to it. Many of the forms seem to pass by almost im- 

 perceptible degrees into similar forms in the neighbouring 

 genera, such as Purpura, Ricinula, Fusus, and Trophon. A 

 line of some sort is attempted to be drawn, by requiring two 

 characters to constitute a murex : namely, that the varices 

 shall be true — that is, indicating by their margins that they 

 have formed outer lips at periods of arrested growth ; and 

 that this canal shall be covered wholly or partially by a 

 columellar plate turned towards its outer margin. In endea- 

 vouring to apply this line, I have admitted certain species 

 with doubt, Blainvillei, dubius, cristatus, &c, omitting others, 

 such as horridus, buxeus, &c, as belonging rather to the 

 Purpuridae ; others, such as laminiferus, carduus, luculentus, 

 as Trophons or Fusi ; and decussatus, fiscellum, &c, as 

 Ricinula?. M. gyratus and muricatus will help to complete 

 what may be considered a good genus, Latiaxis. M. salebro- 

 sus and its allies perhaps rightly form the genus Vitellaria. 

 Thus there will be about twenty species omitted from 

 those enumerated in the latest (Reeves') Monograph. On 

 the other hand, about sixty-five undoubted murices have been 

 added, raising the revised list to two hundred and forty. 



B 



