(v.) 



Fig. 10. 



Copy of tracings showing reflex contraction of the 

 extensor of the second segment and of the abdominal 

 muscles. Xote the difference in latent period of about 

 four seconds. 



Figs. 11 and 12. 



Diagrams showing the arrangement of tendons inserted 

 into the central end of the ba^i-ischium of a Brachyuran. 



Bp = Breaking plane. 



Z/= Long flexor. 



le = Long extensor. 



sf = Short flexor. 



se ■= Short extensor. 



Fig. 1 2 is after Fredericq. 



Fig. 13. 



Showing anatomy of the Hmb in the region of the 

 breaking plane in an edible crab. 



Bp = Breaking plane. 

 le = Long extensor. 

 se = Shcrt extensor. 



The dotted line tlirough a shows the direction in which 

 a knife can be passed up to the breaking plane. 



Fig. 14. 



Diagram of transversj section through limb at level 

 of breaking plane showing attachment of the extensors on 

 either side of the slantino; ioint a. 



