INDENTED. 165 



the shores of most temperate and tropical countries. Fig. 333, 

 J. Fragilis. 



JATARONUS. Adanson. Chama, Auct. 



IBERUS. Montf. Carocolla, Lam. 



IBLA. Leach. Fam. Pedunculated Cirripedes, Lam. — Descr. 

 Four valves, posterior pair elongated, anterior pair short, trian- 

 gular ; pedicle cylindrical, contracted at the base, hairy. — 

 Obs. I. Cuveriana (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. 



JESITES. Montf. A minute fossil resembling Galeolaria. 



ILOTES. Montf. Orbiculina, Bl. A genus of microscopic 

 Foraminifera. 



IMBRICARIA. Schum. Conohelix, Sw. 



IMBRICATED. {Imbrex, a tile.) A shell is said to be imbricated 

 when the superficial laminae are arranged over each other in the 

 manner of tiles. 



IMPERATOR. Montf. A genus composed of species of the genus 

 Trochus, Auct. with whorls angulated and stellated^ having an 

 umbilicus. Ex. T. Imperialis. Some of the shells named Impe- 

 rator in the British Museum belong to the genus Calcar, Montf. 

 having no umbilicus. 



IMPRESSION. See Muscular Impression. 



INCRASSATED. (Crassus, thick.) Thickened, as the hinge of 

 Glycimeris, fig. 67- 



INCURVED. Turned inwards or bent forwards. Applied to sym- 

 metrical shells, when the point of the apex turns towards the 

 anterior extremity, as in Patella. The apex of a shell is said to 

 be incurved when it is bent inwards, but not sufficiently so to be 

 described as spiral. Ex. Ammonoceras, Lam. fig. 477. 



INDENTED. (In, in ; dens, a tooth.) Exactly the reverse of 

 Dentated; meaning a series of small cavities, such as might be 

 produced by the entrance of teeth. The cast of a dentated surface 

 would be indented. 



