220 



THE MORPHOLOGY OF THE COMMON CRAYFISH. 



processes, and the disposition of the vascuLu' canals in its 

 interior gives it the appearance of being radially striated. 

 Tlie setae, so abundant in the adult, are very scant}- in 

 the newly hatched young ; and the great majority of tliose 

 which exist are simple conical prolongations of the ini- 



(. J 



Fig. 60. — Astacus fliiviatilis. — Newly-hatched young' ( x fi). 



calcified cuticle, the bases of which are not sunk in pits 

 and which are devoid of lateral scales or processes. 



The young animals are firmly attached to the ab- 

 dommal appendages of the parent in the manner already 

 described. They are very sluggish, though they move 

 when touched ; and at tbis period they do not feed, but 



