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 tbe 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. 



