238 PYRAMIDELLID. 
Shell subulate, turreted; whorls longitudinally plicate; aper- 
ture ovate, inner lip with a single plait, outer lip frequently 
lirate within. 
Sygnona, A. Ad., 1860. 
Disir.—10 sp. Japan. S. gracillima, A. Ad. 
Shell subulate, straight, vitreous, banded, polished ; whorls 
flat, suture impressed; aperture oblong, inner lip obliquely 
plicate in the middle, outer lip simple, acute. They are readily 
distinguished from the more oval Odostomia—the species of 
which are white and destitute of colored markings. Syrnola, in 
fact, are small slender Obelisci with a single columellar plait. 
AMATHIS, A. Ad., 1861. Subulate, smooth, polished, aperture 
dilated, rounded, acute behind, inner lip with a single plication. 
6sp. Japan. 8S. Virgo, A. Ad. 
SyRNoLopsis, Smith. 
Distr.—S. lacustris, E. A. Smith (lxviii, 15, 16). The only 
species, from Lake Tanganyika, HE. Africa (fresh water), is 
yellowish horn-color, banded with white beneath the suture. 
Shell subulate,smooth, imperforate; aperture broadly sinuated 
at the base, outer lip sinuous, slightly thickened, produced 
below, furnished far within with one or two prominent lire ; 
columella with a distinct plait. Operculum unknown. 
Famity PYRAMIDELLID 4. 
Shell turriculated, columella with several anterior plications. 
Operculum corneous, subspiral, the columellar margin sinuated. 
Animal with broad-shouldered, ear-shaped tentacles, connate 
at the base; eyes immersed at their inner sides ; mantle enclosed, 
with a rudimentary siphonal fold; foot produced and truncate 
anteriorly, with a fold or mentum in front. Lingual teeth none, 
or rudimentary. 
The Turbonillide, just described, have been usually referred 
to this family, and in fact their distinction is one of convenience 
only, the number of columellar plications or their absence being 
characters of small importance. 
“The Pyramidellide present subjects of much interest to the 
student of extinct mollusca; numerous forms, bearing all the 
aspect of being members of this family, occur among the fossils 
of even the oldest stratified rocks. Many of them are gigantic 
compared with existing species, and the group, as a whole, may 
be regarded rather as appertaining to past ages than the present 
epoch.”— FoRBEs. 
PYRAMIDELLA, Lam. 
Etym.—Diminutive of pyramis, a pyramid. 
Distr.—25 sp. W. Indies, Australia,Japan. P. plicata, Lam. 
(Ixviii, 11). Fossil. Cretaceous. 
