PLATE XXVII. 
Fig. 1. ANODONTA cygnea. 
Anodonta cygnea, ham. Syst. 
Mytilus cygneus, Mont. Test. Brit. p. 171- 
M. cygneus, var. B. Mat. and Rack, in Lin. Tr. viii.p. 109. 
Fig. 3, 4. ANODONTA cygnea, young. 
Fig. 2. ANODONTA stagnalis. 
Anodonta stagnalis, Sowerby's Miscell. pi. 16. 
Mytilus cygneus, Mont. Test. Brit. p. l^l.-^-Mat. and Rack, in Lin. Tr. viiii p. 109. 
