170 HIPPONTX. 



nites, Auct. whicli are swelled towards the apex, and contracted 

 near tlie centre. B. Hastatus, Auct. PI. xxii. fig. 468. 



HIMANTOPODA. Schum. Malleus, Auct. 



HINDSIA. A. Adams, ZooL Prac. 1851. A genus composed of 

 Triton Acuminata, (Eeeve's Monograph) and similar species, of 

 which there are about a dozen, agreeing with each other remark- 

 ably well in characters, which separate them from other groups. 

 They have no distinct varices, properly so called, such as distia- 

 guish the true Tritons, excepting a large one immediately behind 

 the aperture, which is rather small, with the lips produced and de- 

 tached. The general form is that of Nassa, but the caudal canal 

 is not turned suddenly over the back, but long and slightly re- 

 curved. Ex. T. acumiaatum. PL xxviii. fig. 599. 



HINGrE. The edge of the bivalve shells near the umbones, 

 including the teeth and ligament. 



HINNITES. Defrance, 1831. A generic name proposed for 

 Pecten Pusio, Auct. remarkable for the irregularity of the 

 outer surface, which would almost lead to the belief of its being 

 an attached shell. The monograph of this genus in the Author's 

 Thesaurus Conchyliorum contains three species. PL xx, fig. 173, 

 H. Pusio. 



HIPPAGUS. Lea. {Horse boat?) A minute fossil shell, re- 

 sembHng Isocardia in form, but destitute of hinge teeth. H. 

 Isocardioides. PL vi. fig. 128. 



HIPPO CHEENES. Montfort, 1810. Species of Eostellaria, 

 Auct. with the outer lip spread. E. Columbaria. PL xviii. 

 fig. 403. 



HIPPONTX. Defrance, 1819. ('iTTTroc, hippos, horse ; ow^, onyx, 

 nail or hoof.) Fam. Eudistes, Lam. — Descr. Inequivalve, sub- 

 equilateral, rather irregular, destitute of ligament and hinge 

 teeth ; lower valve attached, flat, sub-orbicular, vsdth a muscular 

 impression, composed of two luniilate portions, meeting at one 

 extremity, and presenting the form of a horse-shoe ; upper valve 

 conical ; with the apex inchned backwards, and the muscular 

 impression marginal. — Obs. The earlier naturalists having only 

 met with the upper valve of these shells, placed them among the 



