INOCERAMUS. 53 
VBLA. Leach. Fam. Pedunculated Cirripedes, Lam. Descr. Four 
valves, posterior pair elongated, anterior pair short, triangular ; 
pedicle cylindrical, contracted at the base, hairy. Obs. I. Cuve- 
riana, fig. 40, is brought from Kangaroo Island. 
ICTHYOSARCOLITES. Desmarest. Fam. Ammonacea, Lam. 
Descr. Chambered, slightly arcuate, laterally compressed; septa 
simple, leaving triangular articulations imbricated like the thick 
muscles of a fish. 
JE'SITES. Montf. A minute fossil resembling Gatrotaria. 
YLOTES. Montf. Orsicutrya, Bl. A genus of microscopic 
Foraminifera. 
IMBRICATED. (Jmbrez, a tile.) A shell is said to be imbricated 
when the superficial laminee are arranged over each other in the 
manner of tiles. 
IMPERA’TOR. Montf. A genus composed of species of the ge- 
nus Trocuus, Auct. with whorls angulated and stellated, having 
an umbilicus. Hx. T. Imperialis. Some of the shells named 
Imperator in the British Museum belong to the genus Calcar, 
Montf. having no umbilicus. 
IN’'CRASSATED. (Crassus, thick.) Thickened, as the hinge of 
Glycimeris, fig. 67. 
INCURV’ED. Turned inwards or bent forwards. Applied to 
symmetrical shells when the point of the apex turns towards the 
anterior extremity, as in Patella, fig. 229. The apex of ashell is 
said to be incurved when it is bent inwards, but not sufficiently 
so to be described as spiral. Hx. Ammonoceras, Lam. fig. 477. 
INDEN’TED. (In, in; dens, a tooth.) Exactly the reverse of 
DeENTATED ; meaning a series of small cavities, such as might be 
produced by the entrance of teeth. The cast of a dentated sur- 
face would be indented. 
INE’QUIVALVE. (quus, equal; valva, valve.) The two prin- 
cipal valves differing from each other in diameter or convexity. 
INFERIOR VALVE. Is that which is attached to sub-marine 
bodies. Only applied to attached bivalves. 
IN’FEROBRANCHIA’TA. Bl. The fourth family of the se- 
cond section of Paracephalophora Monoica, Bl. containing no 
testaceous mollusca. 
IN’'FLATED. Swelled, as Bulla, fig. 250, 252. This term can 
only be applied to rotund shells, of a light, thin texture; in othe1 
cases we should use the word VENTRICOSE. 
INFUNDIBULUM. Montf. (A funnel.) A genus formed of 
those species of Catyptrma, Lam. which having a spiral septum, 
so nearly resemble Trochus that some authors have placed them 
in that genus. One species is named Patella Trochiformis. 
Fig. 237. 
INOCER’AMUS. Sow. Fam. Malleacea, Lam. Margaritacea, Bl. 
Deser. Thick, inequivalve, sub-equilateral, triangular, deep, with 
