PLEUROTOMIDZ. 161 
Section PLEUROTOMELLA, Verrill, 1873. Shell somewhat tur- 
reted ; apical whorls smooth; the others shouldered and ribbed, 
but with a smooth concave surface above the shoulder ; lip-sinus 
wide, very deep; canal short. Animal blind. 
Section MrrromorpHa, A. Adams, 1865. Shell small, Mitri- 
form, with revolving lire, and sometimes longitudinally plicate; 
columella straight, bearing a number of short plice or teeth 
upon it; lip acute, smooth within, scarcely sinuated posteriorly. 
California, Japan. 
This group has sometimes been referred to Mitra (see Manual, 
iv, 145), but the armament of the columella is not always present, 
and when it is, it more resembles a set of small callous deposits 
than revolving plice. 
Subgenus APHANITOMA, Bellardi, 1875. . 
Shell fusiform; sinus scarcely apparent; columella nearly 
straight, biplicate ; canal rather short, slightly curved. Tertiary 
only. Hurope. 
Genus HALIA, Risso, 1826. 
Shell oval-oblong, ventricose, thin, fragile, shining, smooth ; 
spire obtuse ; aperture oval; columella truncated at the base ; lip 
simple, arcuated, slightly sinuous. 
One living species, Atlantic near Cadiz, and N. W. Africa; 
fossil, a species in the pliocene of N. Italy. 
The classification of this mollusk has a long and interesting 
history, which is given with some detail in a paper by Dr. Paul 
Fischer, entitled “‘ Monographie du genre Halia Risso (Priamus 
Beck), published in Journal de Conchyl., 2d ser., iii, 141. 
There was great uncertainty until within comparatively recent 
times, as te its habitat—whether terrestrial or marine, and the 
animal remained unknown until 1858. Various ancient authors 
classed it successively as a Helix, Buccinum, Bulla, Bulimus, 
Achatina (Lamarck), Cochlicopa (Pfeiffer : Helicidz). 
In 1838, Deshayes published the genus Priamus, Beck, and 
made it an operculated marine shell between Buccinum and 
Struthiolaria; and since that period and up to 1858 the shell 
has been generally classed in the neighborhood of the Strombs 
or Buccinide. 
Hermannsen, in 1846, discovered that Priamus was identical 
