LIST OF WOODCUTS. 



PAGE 



Frontispiece. The Common Crayfish, Astacus fluviatilis, (male) 

 Fig. 1. AstaciLs fluviatilis. Side view of the male. . . 6 



,, 2. ,, ,, DoPvSAL views of MALE AND FEMALE 18 



,, 3. ,, „ VeNTEAL VIEWS OF MALE AND FEMALE 21 



>> "• >» »» 



,, 4. ,, ,, The gills 



,,5. ,, „ Dissection feom the doesal side 



(male) .... 

 Longitudinal veetical section of 



THE ALIMENTAEY CANAL 



A gasteolith oe " grab's eye" 

 Attachment of young to swim 



meeet of mother 

 Steuctuee of the stomach .' 

 Longitudinal section of the sto 



MACH 



eoof of the stomach, from within 

 Dissection from the side (male) 

 Alimentary canal feom above 

 Blood corpuscles . 

 Tr'ansveese section of thoeax , 

 The heaet 



Steuctuee of the gills 

 The geeen gland . 



26 



28 



29 

 30 



41 

 53 



56 

 60 

 62 

 65 

 68 

 70 

 72 

 76 

 83 



