282 



POPULAR CONCHOLOGY. 



Xu.cu.la uucleu-i. 



a large spoon-shaped one in the middle ; hinge curved or 

 straight; bosses contiguous and curved; liga- 

 ment partly internal; epidermis green, or 

 dark olive brown. Animal, subtriagonal, its 

 mantle freely open, without siphonal tubes, 

 and with plain edges ; foot deeply grooved, 

 and forming an ovate pedunculated disk 

 with serrated edges ; one, in each pair of 

 labial palpi long, curled, linear, and fim- 

 briated at its margins ; the other short and filiform.* — 34 

 species f ; also fossil. 



The localities of this genus are the Baltic and Medi- 

 terranean, the Indian Seas, the English Channel, &c, 

 where they are met with on the sand and mud, either on 

 the open coast or at the mouth of rivers. The shell is 

 generally pearly inside. 



Nuculina. JD'Orb. — Shell distinguished from the 

 former genus by the few teeth in a single row, by a 

 Cardium-like side tooth, and by the perceptible ligament 

 below the boss. Animal unknown. 



The only known species is N. miliaris of Deshayes. 



Leda. Schum. — Shell equivalve, inequilateral, oblong, 

 produced posteriorly, closed, smooth, or con- 

 centrically striated, invested by an epidermis; 

 margins smooth; beaks approximated incurved ; 

 inside more or less nacrous ; hinge line angu- Uda caudatat 

 lated, and formed as well as the ligament 

 like Nucula ; pallial impression with a sinus. Animal 

 oblong, mantle open in front, with simple, or fimbriated 

 margins, furnished posteriorly with two partially united, 



* Forbes's British Moll. 



f Sowerby's Thesaurus. 



