MONOGRAPH OF THE GENUS 

 HINNITES. 



Char. Gen. Molluscum accephalopodum monomyarium. 

 Testa ad haerente, bivalvi, iiiccquivalvi, irregular!, biauricu- 

 lata : cardine recto, foveola trigona, centrali, cartilaginem reci- 

 piente ; ligamento linearo, umbonibus contiguis. 



Obs. The alledged difference between this genus and 

 Pecten, consists in the disputed fact, that the shells of this 

 genus are attached to submarine substances by the surface of 

 the lower valve, and therefore, in giving the characters as 

 above, I have used the word ' adJiarente ' in opposition to 

 the term ' libera' which is appUed to the genus Pecten, 

 because if the genus is to be adopted, that will be its dis- 

 tinction. At the same time, however, I am rather inclined 

 to entertain the opinion expressed by G. B. Sowerby, Senr. 

 (Zool. Journ.) that the Hinnites as well as the Pectines, are 

 provided with a byssus ; but that, in the case of the former, 

 the shell growing in a confined situation, " becomes 

 pressed close to, and takes the shape of the substances to 

 which it adheres, and the extremely rare occurrence of an 

 opportunity of observing its byssus may have given rise to 

 the idea of its being adherent by its outer surface to those 

 substances." 



DESCRIPTIONS. 



1. H. siNuosus (pi. XX. f. 1, 2, 3.) Pecten pusio, distor- 

 tus, nonnull. 



T. oblonga, tenui, confertim radiatim striata,^ striis scabns ; 

 auriculis inaequalibus, radiatim scabris : valva dextra prope 

 marginem ventraleni plerumque irregulariter depressa, 

 polita. 



Shell oblong, thin, closely striated, striae radiating, sca- 

 brous ; ears unequal, with scabrous radiated striae ; outside 



