TROPHON. 315 



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

 coin from the Laskeyan mint, is exotic ; Turton's speci- 

 men shows it to be a Lachesis. 



Genus V. TROPHON*, ? De Montfort. PL VI. f. 2. 



SHELL spindle-shaped, never umbilieate, lengthwise plaited 

 or having laminar (occasionally varicose) ribs, and sometimes 

 cancellated by spiral ridges : epidermis none : spire elongated ; 

 apex mammiform : 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 : egg-cases sepa- 

 rate, membranous, hemispherical, and attached by the circular 



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- 

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

 on its having a very deep and conspicuous umbilicus, 

 as distinguishing Trophon from Buccinum. The genus, 

 as now recognized, possesses scarcely one of the cha- 

 racters attributed to it by the founder. The name, 

 however, is immaterial. Whether Trophon is distinct 

 from Fusus, or is merely 



" et nomen et genus inutile,' 



are other questions that require much consideration. 

 I adopt the genus provisionally. 



Trophon frequents the laminarian and coralline zones, 

 and appears to be restricted to the North Atlantic. 



* Contracted from Trophonius, the name of a mythological deity. 



