GASTEROPODA. 143 



Distr., 60 sp. Tropical seas, W. Indies, Medit., Cape, India, China, 

 Australia, New Zealand, Pacific, Peru. 



Fossil, 360 sp. (including litorina) L. Silurian. Universal. 



PHASIANELLA, Lam. Pheasant-shell. 



Syn., eutropia (Humphr,) Gray. Tricolea, Risso. 



Type, P. australis. PL X., fig. 3. 



Shell elongated, polished, richly coloured ; whirls, convex ; aperture oval, 

 not pearly ; inner lip callous, outer thin ; operc. shelly, callous outside, sub- 

 spiral inside. 



Animal with long ciliated tentacles ; head-lobes pectinated, wanting in the 

 minute sp. ; neck-lobes fringed ; sides ornamented with 3 cirri ; branchial 

 plume long, partly free ; foot rounded in front, pointed behind ; its sides 

 moved alternately in walking ; lingual teeth even-edged ; laterals 5, hooked, 

 denticulated; uncini about 70, gradually diminishing outwards, hooked and 

 denticulated. 



Distr., 25 sp. Australia, large sp. India, Philippines ; small sp. Medit., 

 Brit., W. Indies, very small sp. 



Fossil, 70 sp. 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. 



IMPERATOR, Montf. 



Type, I, imperialis, PI. 10, fig. 4. Syn., calcar. 



Shell trochiform, thick, with a flat or concave base; whirls keeled or 

 stellated ; aperture angulated outside, brilliantly pearly ; operc. shelly. 

 Distr., 20 sp. ? S. Africa, India, Australia, New Zealand. 



Fig. 87.* 



TROCHUS, L. 

 Etym., trochus, a hoop. 



Syn., cardinalia, tegula, and livona, Gray. Infundibulum, Montf. Chlo- 

 rostoma, Sw. Trochiscus, Sby. Monilea, Sw. 



Types, T. niloticus. PL X., fig. 5. T. zizyphinus. Fig. 87. 



* Fig. 87. Trochus zizyphinus, L., Pegwell Bay, Kent. 



