MUREX. 43 



varicibus breviter frondosis, frondibus numerosis parvis sub- 

 dilatatis. — A small dull-coloured species, with short frauds 

 which are a little dilated at the extremities. 



201. RUSTicus, f. 241, Reeve. — Testa pyramidata albida 

 violaceo-frondosa, spiraliter lirata, varicibus seuis crassis, 

 frondibus aculeatis, radiatis, spira elongata, anfractibus 

 angulatis, apertura parva, canali brevi lato, clauso, margine 

 serrato. — A pyramidal shell with narrow dark-coloured fronds. 



201a. vitellus, f. 249, Brocl.— Testa fusiformis, sub- 

 angulata, utrinque acuminata, scabra, alba, fusco-nigrescenti 

 super costas alternatis lineata, spiraliter costata, costis acutis, 

 ad varices breviter spinosis ; varicibus septenis, fronte 

 imbricatis ; spira pyramidata anfractibus angulatis, ad 

 canalem breviter imbricatis ; apertura ovata, margine externo 

 crenato. — In some specimens, the spiral ribs are scarcely 

 developed into spines, and the shell appears much less like a 

 rnurex. M. lepidus, Reeve, seems to present no characters 

 which should cause it to be regarded as distinct from this 

 species, the dark lines only being substituted by irregular spots. 



201b. dubius, f. 250, Sowerby. — Testa fumoso-fusca angu- 

 latim subfusiformis, utrinque acuminata, spiraliter striata; 

 varicibus septenis brevibus angulatis, frondibus subdistanti- 

 bus spinoso-tuberculatis ; apertura subtrigona, intus mar- 

 giuem externum quinquedentata, canali fere clauso. — A 

 darkly coloured shell whose place in the genus is, as the 

 name is intended to imply, at least doubtful. The varices 

 are, however, often distinct, and the laminar plate over the 

 canal is present, although narrow. 



201c. hexagonus, f. 257, Lamarck. — Testa elongato-fusi- 

 formis, pallide lutescens, spiraliter distanter costata ; varicibus 

 senis, angulatis, ultimi anfractus spinoso-digitatis, inter 

 digitos breviter spinosis, apertura subpyriformis, elongata, 

 margine externo intus dentato, canali elongato, acuminato, 

 varices spinis purpureis. — The spines, which are only developed 

 in the later varices are sometimes brown and sometimes 

 delicate purple. 



201d. cristatus, f. 258, Brocchi, — Testa angulatim fusi- 

 formis, fidva vel rubescens, spiraliter striata, subdistanter 

 lirata; varicibus octonis, frondibus angulatim exfoliatis ; 

 apertura angulata, margine externo intus denticulate — The 

 fronds being exfoliated in the later stages of growth, I am 



