318 PLEUROTOMARIID”. 
expanded, with depressed base; aperture large, rounded, sub- 
sinuated behind, pearly within; columella revolute, acute; lip 
simple. 
Apparently not an operculated shell. The whole appearance, 
especially the pearly interior, reminds one of tle Trochide, and 
Mr. Adams is evidently mistaken in referring it as he does to 
the family Valvatide. 
BRovDERIPIA, Gray. 
Etym.—Named in honor of W. J. Broderip, Esq., the distin- 
guished conchologist. 
Distr.— 3 species. Philippines, Grimwood’s Island, South 
Seas.—Cumine.  B. tridescens, Brod. (1xxxi, 79, 80). 
Shell minute, limpet-shaped, with a posterior submarginal, 
non-spiral apex ; aperture oval, as large as the shell, brilliantly 
nacreous. 

VELAINELLA, Vasseur. 
Htym.—Named after Charles Velain, a French naturalist. 
Distr.—V. columnaris, Vasseur (1xxiii, 5). Eocene; Nantes, 
France. 
Shell spiral, dextral, extremely elongated, thick and solid, 
nacreous within; aperture oval-oblique, peritreme continuous, 
left margin with a slight columellar swelling. 
The nacreous interior brings this into the Trochide, but it is 
very distinct from any of the preceding forms. 
Famity PLEUROTOMARIID A. 
Shell more or less conically elevated, turreted or trochiform, 
with a marginal slit in the upper part of the outer lip, or a row 
of perforations in the upper part of the whorl; aperture pearly 
within. 
PLeUROTOMARIA, Defrance. 
Ktym.—Pleura, side, and tome, a notch. 
Disir.—4 sp. West Indies, Moluceas, Japan. Pl. Quoyana, 
Fischer and Bernardi (Ixxxii, 84). Fossil, 400 sp. Cambrian to 
Cretaceous; North America, Europe, Australia. 
Specimens from clay str ata retain their nacreous inner layers; 
those from the chalk and limestones have lost them, or they 
are replaced by crystalline spar. Pleurotomariz with Wavy 
bands of color have been obtained in the carb. limestone of Lan- 
cashire. In this extensive group there are some species which 
rival the living turbines in magnitude and solidity, whilst others 
are as frail as Ianthina. 
Shell trochiform, solid, few-whorled, with the surface variously 
ornamented ; aperture subquadrate, with a deep slit in its outer 
