MYARIA. 351 



The shell is slightly inequilateral, transverse, nearly oval or 

 round, slightly gaping at the sides : the hinge is composed 

 of either one or two cardinal teeth in each valve, with a 

 long narrow pit lying between them for the insertion of the 

 ligament, which is duplex, partly external and thin, partly 

 internal and short. The pallial impression has a large sinus. 

 Sowerby established the genus Cumingia for the intro- 

 duction of a new and interesting species. The shell exhibits 

 the unusual character of having two strong lateral teeth in 

 one valve, and none in the other; but approximates, in other 

 respects, to that of the Am^^Jiidesmata. Tew instances are 

 on record in which a naturalist has been honoured by the 

 introduction of his name into the nomenclature of genera ; 

 but the indefatigable zeal which has been displayed by Mr. 

 Cuming fully entitle him to such a distinction. 



Family XV. Myaria. 



Oh ! the wild sea-beach 

 Is lone and dull when men unwilling roam, 

 Vex'd with the salt spray or the whistling wind, 

 Heedless of shells or sea-weeds : yet not lone 

 To him who walks with Nature, noting well 

 Her perfect works, however small they be. 



A natural link is formed by the family Myaria between 



