62 



ing the ligament attached to it, is the anterior; while 

 in the Donax, it is exactly the reverse, the ligament be- 

 ing affixed to the shortest side as in theTellens, to which 

 consequently they are more nearly allied than to the 

 G.Venus, though without the flexuous plait. 



Internal margin of the 



Valves smooth, or nearly so, 



Donax scortum 



pubescens 



compressa 



cuneata 



Donax granosa 



columbella 



veneriformis 



australis 



deltoides 



.-. epidermia 



radians 



bicolor 



abbreviata 



vittata 



Donax triquetra. 



Internal edge of the Valves distinctly dentated or 

 crenulated. 

 Donax ringens Donax meroe 



rugosa scri P ta 



Cayennensis trunculus 



elongate flabagella 



denticulata cinatinum 



cardioides Martinicensis 



