FUSIDA. 127 
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 Neptuniine ; 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 rustnaz. Columella not plicate, not tortuous. 
Subfamily rascrorarun®. Columella tortuous with oblique 
plaits or plications. 
Subfamily prycuarractin”%. Differs from Fasciolariine in 
lingual dentition, and includes only three small boreal species. 
Subfamily PERISTERNIINaZ. Columella with transverse pli- 
cations. 
SuBraMity FUSINZ. 
Fusus, Lamarck. 
Syn.—Aptyxis, Troschel. Colus, Humph. Syrinx, Bolt. 
Disir.—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 strigze 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 Buccinide. 
COLUMBARIA, von Martens. Shoulder of whorls spinose, a 
revolving ridge on the lower part of body-whorl. Dentition 
similar to the Pleurotomide. £. Pagoda, Lesson (xlvii, 71). 
SINISTRALIA, H. and A. Ad. Shell reversed, fusiform; canal 
long; whorls rounded. F. Maroccensis, Gmel. (xlvii, 72). 
HADRIANA, Bueq. and Dautz. Proposed for the European F. 
craticulatus, 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 Neptunex, but its high spire and strongly costate 
whorls show that it is more nearly 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, 
