264 MANUAL OF THE MOLLUSCA. 
hooked, denticulated; uncini about 70, gradually diminishing 
outwards, hooked and denticulated. 
Distribution, 25 species. Australia, large species; India, 
Philippines, small species; Mediterranean, Britain, West 
Indies, very small species. 
Fossil, 70 species. Devonian (?). Europe. 
The similarity of the existing Australian fauna to that of the 
European oolites strengthens the probability that some, at 
least, of these fossil shells are rightly referred to Phasianella. 
Fig. 114.* 
IMPERATOR, Montfort. 
Type, I. imperialis. Pl. X., Fig. 4. 
Synonym, Calcar. 
Shell. trochiform, thick, with a flat or concave base; whorls 
keeled or stellated; aperture angulated outside, brilliantly 
pearly ; operculum shelly. 
Distribution, 20 species? South Africa, India, Australia, 
New Zealand. 
Trocuus, L. 
Etymology, trochus, a hoop. 
Synonyms, Cardinalia, Tegula, and Livona, Gray. Infundi- 
bulum, Montfort. Chlorostoma, Sw. Trochiscus, Sby. Monilea, 
Sw. 
Types, T. niloticus. Pl. X., Fig. 5. T. zizyphinus. Fig. 114. 
Shell pyramidal, with nearly a flat base; whorls numerous, 
flat, variously striated; aperture oblique, rhombic, 
pearly inside; columella twisted, slightly trun- 
cated; outer lip thin; operculum horny, multi- 
spiral, Fig. 115 (T. pica). 
Animal with 2 small or obsolete head-lobes be- 
tween the tentacles; neck-lappets large; sides 
ornamented with lobes, and 3—5 cirri; gill very 
1ong, linear; lingual teeth 11, denticulated; uncini — 90, 
diminishing outwards- 
| * Fig. 114, Zrochus zizyphinus, L., Pegwell Bay, Kent, 
Fig. 115. 
