APLUSTIRIDA. 361 
truncate anteriorly ; outer lip produced behind. A. Cranchii, 
Leach. 
ALIcuLA, Ehrenberg, 1831. Shell subcylindrical, transversely 
striate. 3 sp. ue ae A. translucens, A. Ad. Japan. 
LEUCONYX, H. and A. Ad.,a Se new genus of Bullide, 
is the spatulate hinge process of Pholas costata. 
Famity APLUSTRID. 
Teeth, central none ; laterals numerous, uniform. Head with 
the frontal disk produced into large ear-like tentacular lobes 
folded over the back of the shell, and furnished with bifid labial 
appendages; eyes sessile at the inner bases of the tentacular 
lobes. Mantle with the inner margin thin and membranous, the 
outer forming a thick, fleshy lobe, curving round the spire of 
the shell; branchial plume long and single. Foot large and 
membranous, auriculate in front, rounded behind. 
The shell has usually a short spire, the last whorl inflated, 
aperture anteriorly distinctly effuse, columella somewhat thick- 
ened, rarely twisted, but always anteriorly truncated. 
ApiustruM, Schumacher. 
Etym.—Aplustre, a ship’s flag. 
Distr —1 sp. Coral reefs, East Indies. A. aplustre, Linn. 
(Ixxxvii, 43). 
Shell oval, ventricose, highly colored; spire wide, depressed ; 
aperture truncated in front; outer lip sharp. 
Differs from Bullina by its smooth, somewhat thinner shell, 
more depressed spire, the columella being very thick, slightly 
twisted and truncated in front. 
Buuiina, Fer. 
Distr.—B. lineata, Wood (|xxxvii, 44). 
Shell oval, rather solid, subumbilicated; spire distinct; whorls 
with revolving strie ; columella arcuated, obliquely truncated in 
front; outer lip crenelated. 
KLEINELLA, A. Ad., 1860. Shell ovate, thin, umbilicated, can- 
cellated, aperture produced anteriorly, inner lip not plicated. 
Resembles Actzon, but without columellar fold. Japan. B. 
cancellaris, A. Ad. 
Hypatina, Schum., 1817. 
Distr.—Recent, several sp. Fossil. Jurassic—. 4H. physis, 
Linn. (Ixxxvii, 45). 
Shell ventricose, thin, smooth, not umbilicated, with a thin 
epidermis ; usually banded; spire involute; columella arcuated, 
reflected. 
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