PHASIANELLIDA. 303 
from the elongated species of Trochidse by the calcareous 
operculum. 
PHASIANELLA, Lam. 
Pheasant-shell. 
Distr.—25 sp. Australia, large species; India, Philippines, 
small species; Mediterranean, Britain, West Indies, very small 
species. Fossil, 70 sp. Devonian—; Europe. P. bulimoides, 
Lam. (Ixxix, 6). 
Shell elongated, polished, richly colored; whorls convex ; 
aperture oval, not pearly; inner lip callous, outer thin. Oper- 
culum shelly, callous outside, subspiral inside. 
When the animals of this genus crawl, the foot appears to be 
divided longitudinally into halves, which advance alternately ; 
when the right side moves, the left remains stationary, and when 
this in turn is carried forward, the other half remains as a point 
of support; it may be compared to the amble or canter of a 
horse. In Phasianella proper, the tentacles are ciliated, the 
head-lobes fringed, and the sides of the foot furnished with three 
cirri. In the smaller species, forming the Tricolia of Risso, 
the head-lobes appear to be wanting. The larger species, all of 
which have beautifully variegated shells, are principally from 
Australia, and the smaller ones from the Mediterranean, West 
Indies and South Africa. 
TRICOLIA, Risso. (Eudora, Leach.) Shell thin, spire elevated, 
apex mammillated; suture profound; aperture oval. Small 
species, Mediterranean, etc. P. Niciensis, Risso (1xxix, 7). 
P. pulla, Linn. (1xxix, 8). 
LEIopyRGA, A. Ad. Shell turbinate, thin, smooth, polished ; 
aperture semicircular, shorter than the spire, inner lip thin, colu- 
mella incurved, excavated. P. picturata, A. Ad. 
EUCOSMIA, Carp. Shell small, turbinate, solid, smooth, varie- 
gated, not nacreous; aperture with the margins nearly contin- 
uous, but not callous; columella slightly excavated; axis 
umbilicated. 6 sp. West Coast of N. America. P. variegata, 
Carp. 
Atoyna, A. Adams. 
Distr.—2 sp. Japan. A. rubra, Pease. 
Shell acuminately ovate, imperforate, spire short, conieal, 
acute; whorls flat, smooth; aperture oval; inner lip callous, 
terminating in a strong tooth below; outer lip acute, smooth 
within. 
Curomoris, A. Ad. 
Distr.—Phas. neritina, Dunker (lxxix, 9). Cape of Good Hope. 
Shell ear-shaped, thin, polished ; spire very short; whorls few, 
rapidly enlarging; aperture oval, columella flattened and solid. 
Operculum calcareous. 
