104 Mr, Gray on the Genus Hinnita ofDe France, S^c, [Aug . 



myself perfectly satisfied that it may be considered as the recent 

 type of that genus ; thus, at the same time, adding the genus 

 llinnita (for now the name must be changed, as the termination 

 ites is only used in those genera where the species have only 

 hitherto been found in a fossil state), to the list of recent 

 shells, and erasing it from the catalogue of those genera 

 which are considered by geologists as only to be found in a 

 fossil state. 



The following character may be given to the genus, which 

 should be referred to the family SpondylidcB (nob.) 



Hinnita, nob. Hinnites De France, 



Shell bivalve, inequivalved, adherent immediately, by the apex 

 of the right valve. Valves eared, radiately striated, beaks 

 slightly produced into a triangular area. Byssal groove, none. 



Hinge without teeth ; elastic cartilage placed in a deep groove^ 

 in each valve ; ligament marginal, linear, straight. 



Animal unknown. 



The chief character by which this genus is to be distinguished 

 from Spondylus, is that the hinge is destitute of teeth, and that 

 the facets of both valves are nearly equally extended by the 

 growth of the shell ; instead of the attached one being extended 

 into a long shelving projection, as in the latter, and that the 

 valves are more equal and more distinctly radiately ribbed, and 

 not quite so spinose as most of the species of the latter genus. 



De France, in the work above quoted, has described two 

 fossil species, 1 H. Cortesyi, figured in the Dictionaire des 

 Sciences Naturelle, t. 61, f. 1, and 2, H. Duboissoni, to which 

 I now add as the recent type, 



3. H. Gigantea. 



Shell oblong, outside pale brown, finely radiately-grooved, 

 inside white, hinge margin purple. 



Lima gigantea. Grayj AnrmL Phil. 



Icon. IVood, Catalogue Suppl. t. 2, f. 7, inedited. 



Inhabits. Mus. Brit, 



Shell oblong, rather thick, solid, outside pale brown, orna- 

 mented with numerous small rays, the left valve the most con- 

 vex, the inside white with the hinge margin fine dark purple, 

 the area left by the moving forward of the ligament is also 

 purple, and rather narrow, the grooves for the elastic cartilage is 

 very large and distinct in each of the valves, and quite open, 

 they are extended the whole length of the facet, and consider- 

 ably produced into the cavity of the shell. The muscular 

 impressions are large, and the submarginal impression is orbi- 

 cular ovate, with a considerable inflexion just even with the 

 anterior ear. The length is four inches, the height from hinge 

 to basal edge five inches. 



I shall here take the opportunity, as I neglected it in my con- 

 choiogical essays, of pointing out how the back and the front 



