558 RADULIDiE. 



Sub-gen. mantkllum, Bolten. 



Shell thin, ventricose, oblique; hind side of shell widely 

 gaping. Hinge-margin oblique ; cartilage-pit central, project- 

 ing into the cavity of the shell. 



angulata, Sow. hians, Gmel. 



arcuata, Sow. inflata, Client. 



Basilanica, Adams and Reeve. Loscombii, Leach. 



Cumingii, Sow. orientalis, Adams and Reeve. 



dentata, Sow. rotundata, Sow. 



fasciata, Linn. ventricosa, Soiv. 

 fragilis, Chem. 



Sub-gen. acesta, H. and A. Adams. 



Shell thin, inequilateral, ventricose, radiately striated, slightly 

 gaping. Hinge with the cartilage-pit oblong, elongate, under 

 the anterior auricle. 



excavata, Chem. 



Sub-genus limatula, Searles Wood. 



Shell nearly equilateral, slightly gaping, auricles nearly equal. 

 Hinge-margin thick; cartilage-pit central, large, projecting into 

 the cavity. 



bullata, Born. subauriculata, Montagu. 



Genus LIM.EA, Bronn. 



Mantle margins simple, without tentacular filaments. 



Shell sub-globose, roundly ovate, sub-equilateral, closed ; 

 surface of valves with squamose, radiating ribs ; beaks pro- 

 minent; margins crenate. Cardinal margins rather oblique, 



