102 CASTALIA. 



species of tbe genus Cassis, ^uct. wLicli have the "aperture 

 wide ; outer lip never broad or flattened, but sometimes slightly 

 inflected; inner lip spreading, but never dilated or detached 

 beyond the base into a prominent rim." East Indies. Ex. C. 

 Grlauca. C. Bezoardica. Schum. 1837. PI. xis. fig. 411. 



CASSIDULUS. Humph. The genus Pyrula being restricted to 

 the fig-shaped species, this name is used for the turrited and tur- 

 binated species that remain. C. melongena, &c. but not in- 

 cluding P. perversa. Pulgur. Montf. 



CASSIDULINA, D'Orbigny. A genus of microscopic Porami- 

 nifera. 



CASSIS. Browne, 1756. (A helmet.) Fam. Purpurifera, Lam. 



. Entomostomata, Bl. — Descr. Oval or triangular, ventricose, thick, 

 generally tuberculated, vpith a short varicose spire ; aperture 

 long, sometimes narrow, with the outer lip thickened and re- 

 flected, generally denticulated ; the inner lip spread over the 

 surface of the body whorl, indented and incrassated at its inner 

 edge; canal turned suddenly over the back of the shell. — Hub. 

 Seas of tropical climates. The fossil species are rare, occurring 

 in the tertiary strata. — Obs. The large, common species of this 

 well known genus are used for shell cameos and as ornaments 

 on chimney pieces, grottos, &c. and are remarkable for the 

 triangular disc, presented by the inner Hp, which, in many 

 species, is thickened and spread over the front of the body 

 whorl and the angulated outer lip. The smaller, more rounded 

 species, which have widened apertures, have been separated by 

 Swainson, under the generic name Cassidea. The C. rufa, 

 coarctata, &c. are formed by Mr. Stutchbury into a new genus 

 under the name Ctpr^cassis, for reasons which will be stated 

 under the word. Cassidaria is distinguished by the gradual 

 curve of the canal. Mr. Reeve's monograph contains 43 species. 

 C. tuberosa (diminished.) PL xix. fig. 410. 



CASTALIA. Lamarck, 1819. Fam. Trigonees, Lam. — Descr. 

 Pluviatile, equivalve, inequilateral, trigonal, with corroded um- 

 bones ; hinge with two laminar, transversely striated teeth, one 

 of which is posterior, remote from the umbones, short, divided, 



