FUSIDiE. 121 



family. Stimpson (Am. Jour. Conch.^ i, 60) describes and figures 

 the dentition of an unknown species of Peristernia from the coast 

 of Georgia, which has the essential features of Busycon, and he 

 thereupon places the genus in Neptuniinae ; but it is evident that 

 he was in error, as Troschel figures known species, which are 

 Fasciolariform in dentition as they are in conchological 

 characters. 



Subfamily fusing. Columella not plicate, not tortuous. 



Subfamily fasciolariin^. Columella tortuous with oblique 

 plaits or plications. 



Subfamily ptychatractin^. Difl'ers from Fasciolariinae in 

 lingual dentition, and includes only three small boreal species. 



Svibfamily peristerniin^. Columella with transverse pli- 



Subfamily FUSING. 



Fusus, Lamarck. 



Syn. — Aptyxis, Troschel. Coins, Humph. Syrinx, Bolt. 



Dislr. — 65 sp. Tropical and Subtropical, world-wide. F. 

 Nicobaricus, Lam. (xlvii, 70). Fossil, 300 sp. Bath oolite (?), 

 Cretaceous to Eocene — . 



Shell fusiform; spire long, acuminate, many- whorled; aperture 

 oval, usually striate within ; outer lip simple ; columella smooth; 

 no umbilicus ; canal long and straight. Yellowish brown or 

 light horn-color, sometimes with red-brown strigas or spots ; 

 never banded. Operculum ovate, acute, with apical nucleus. 



The genus, as restricted to the spindle-shaped forms, is sub- 

 tropical in distribution — the northern species usually described 

 as Fusus by the older conchologists being now more correctly 

 referred to the family Buccinidce. 



COLUMBARIA, von Martens. Shoulder of whorls spinose, a 

 revolving ridge on the lower part of body-whorl. Dentition 

 similar to the Pleurotomidse. F. Pagoda, Lesson (xlvii, H). 



siNiSTRALiA, H. and A. Ad. Shell reversed, fusiform ; canal 

 long ; whorls rounded. F. Maroccensis, Grmel. (xlvii, 12). 



HADRiANA, Bucq. and Dautz. Proposed for the European F. 

 craticidatus, Brocchi, which unites the closed canal and varices 

 of Murex with the simple lip and general form of Fusus. 



EXiLiFUSUS, Gabb. Shell very long, slender, fusiform ; spire 

 high ; aperture produced into a long, slender, twisted canal. 



This group differs from the true genus Fusus, as restricted, 

 by its twisted, slender canal. In this character it approaches 

 some of the Neptuneee, but its high spire and strongly costate 

 whorls show that it is more nearl}' allied to the true Fusus. F. 

 Kerri, Gabb (xlvii, 73). Cretaceous ; N. Carolina. 



EXILIA, Conrad. (Exilifusus, Conrad.) Shell very narrow, 

 costate, spire subulate, canal long and narrow. F. pergracilis, 



