UNIVALVES. 



PLATE I. 



Genus. MUREX. 

 Character. A spiral shell, tuberculous; in form oblong, acuminated; the 

 cheek of the mouth standing straight forwards; the spire without sutures; the 

 columella twisted ; beak bent outwards. 



Species. 

 No. 1. Murex aurantia. Shell of a bright orange colour, divaricated with 



numerous streaks of dark red ; mouth of a pale brown. Native place 



unknown. 

 No. 2. Murex lignarius. Shell of a bright orange colour, shaded with streaks 



of purple and white in an unequal manner; the mouth fluted; the columella 



having ridges or folds in its volute ; colour, pale yellow or brown. 

 No. 3. Murex trapezium. Shell of a pale purple colour, invested with streaks 



of black and orange colours ; columella partially fluted ; mouth streaked 



with red lines. 

 No. 4. Murex bandatus. Shell of a dark brown, banded with a double line of 



white upon each folding of the spire ; mouth of a pale brown. 

 No. 5. Murex bandarius. Shell of a dark brown, banded with three bands of 



white and one of red on the first folding of the spire, and with two of 



white on each of the others ; the mouth purple, streaked with brown. 



REMARKS. 



The history of those Shells which are placed by Linnaeus, Knorr, and Gualtieri, in the 

 family or genus of Murex, has been much confused by the number of synonyms, and the 

 imperfections of description. To make this path of Natural History more easy, J shall begin 

 with this genus, of which so much has been written, and of which so little seems to be pre- 

 cisely understood. The word Murex is taken from a term used by Virgil, to describe the 

 famous shell that was anciently found upon the coast of Phoenicia, and which afforded, by 

 means of an animal juice, the splendid and costly purple dye of the Tyrians. This shell, 

 however, it will hereafter be shewn, is of another form, and belongs properly to the 

 genus Polyplex, although resembling in many respects the Murex, which may be called 

 indeed its relative. The true Murex, undoubtedly, varies very much in itself, sometimes 

 having a very long spire, and equally as long a beak, for which reason some writers have 

 been inclined to name them the Fusus or Spindle; but as some of the Murices are, gradus 

 per gradum, shorter in respect to the above parts, such a discrimination seems to be quite 

 uncertain and capricious. It will be observed, that in this Work the distinctions are founded 

 chiefly upon the mouth and spire, whereby we may obtain a more certain and indubitable 

 criterion. 



