16 CALYPTRAA. 
CAL'CAR. Montf. Genus composed of Trocuus STELaRis, 
Lam. and other depressed species of Trochus, which are cha- 
racterized by a stellated keel round the angle of the last whorl, 
but not including T. Imperialis, which is the genus Imperator, 
Mont. The difference is that the latter is umbilicated, and the 
former is not. T. Stellaris, fig. 358. 
CALCE’OLA. Lam. Fam. Rudistes, Lam. and Bl. Deser. 
equilateral inzequivalve, triangular; umbones separated by a 
large triangular disc in the lower valve; cardinal margin 
straight, linear, dentated; lower valve large, deep; upper valve 
flat, semiorbicular, forming a kind of operculum to the lower. 
Obs. Linneus places this singular shell, which is known only in 
a fossil state, in the genus Anomia. Lamarck places it among 
his Rudistes, but Sowerby, in the Genera of Shells, states, that it 
should be added to the family of Brachiopoda: fig. 194, 195, C. 
Sandalina. 
CALLAN’TICA. Gray. Poticires Hispidus, Leach. 
CALLI'RHOE. Montf. p. 362, v. 2. Appears to be drawn from 
the nut or inner portion of a large Belemnites. 
CALLOSITY. A term used in general zoology to express those 
hard, horny tumidities, formed in the skin of some animals, (such 
as the dromedary, for instance,) in those parts which are most 
frequently used. It is not used in this sense by conchologists, 
who apply it to those undefined tumidities or bumps which ap- 
pear in the inner surface and hinge of some bivalve shells. Gly- 
cimeris, fig. 67. Natica, fig. 327, 328. 
CALPURNUS. Montf. Ovuzum Verrucosum, Auct. Distin- 
guished by the small circular tubercle or wart at the back of 
each extremity of the shell. Fig. 441. 
CALYP’TRIDA. Lam. A family of the first section of the 
order Gasteropoda, Lam. containing the genera, Parmophorus, 
Emarginula, Fissurella, Pileopsis, Calyptreea, Crepidula and 
Ancylus; to which may be added, Infundibulum, and other 
genera enumerated in explanation of figures 234 to 246. 
CALYP’TRACEA. Bl. Second family of the order Scutibran- 
chiata, Bl. ‘Shell more or less conical, not spiral, or very 
slightly so; aperture large and entire.’”” Genera, Crepidula, 
Calyptrea, Capulus, Hipponyx, Notréma 
CALYPTRAEA. Lam, Fam. Calyptracea, Lam. & Bl. Deser. 
Conical, patelliform, irregular, with an internal, lateral, salient 
appendage, varying in form. Obs. The internal appendage is 
in some species cup-shaped, in some it juts out of the centre 
like a fork, in others it is only a small flap, and in others it is a 
spiral disc. These last, which are shaped like Trochus, are 
separated by De Montfort, under the appellation InrunpisuLUM 
Trochatella, Sw. The Calyptreea may be known from Crepi- 
dula by the internal appendage, which in the latter is a flat 
plate reaching half way across the aperture. Fig. 234, 235, 236. 
