TROPHOX. 315 



Murex gyrinus of Montagu (not of Linne)^ a base 

 coin from the Laskevan mint^ is exotic ; Tui'ton^s speci- 

 men shows it to be a Lachesis. 



Genus V. TROPHOX^ ? De Montfort. PL VI. f. 2. 



Shell spindle-shaped, never umbilicate, lengthwise plaited 

 or having laminar (occasionally varicose) ribs, and sometimes 

 cancellated by spiral ridges : epklei'mis none : spire elongated : 

 apex mammilbrm : outer lip seldom notched or toothed within : 

 pillar smooth, more or less twisted: canal usually long and 

 beak-like, open throughout : operculum pear-shaped, flexuous ; 

 nucleus placed at the inner base of the mouth : er/g-cases sepa- 

 rate, membranous, hemispherical, and attached by the circular 

 base. 



De Montfort has the credit of instituting this genus ; 

 but his definition does not correspond with our idea of 

 it. He describes the shell as globular, with an expanded 

 mouth, the outer lip foliated or plaited, the base umbi- 

 licate, and the canal short ; indeed he lays great stress 

 on its ha\'ing a very deep and conspicuous umbilicus, 

 as distinguishing Trophon from Buccinum. The genus, 

 as now recognized, possesses scai'cely one of the cha- 

 racters attributed to it by the founder. The name, 

 however, is immaterial. AVhether Trophon is distinct 

 from FusuSj or is merely 



" et nomen et o:enus inutile," 



are other questions that requii'e mucli consideration. 

 I adopt the genus provisionally. 



Trophon frequents the laminarian and coralline zones, 

 and appears to be restricted to the North Atlantic. 



* Contracted from Troplionius. the name of a mythological deity. 



p 2 



