SEA-FISHERIES LABORATORY. 367 



of the fifth sternal muscle chamber. It arises from the 

 anterior face of the fifth thoracic endosternite, and passes 

 outward and downward, and is inserted on a long tendon 

 on the dorsal side of the basi-ischium (ex. B.). 



The flexor lies in the ventral and posterior part of the 

 fifth sternal muscle chamber. It arises from the median 

 plate, and passes downward and outward. Its insertion 

 is on a fairly broad tendon on the ventral side of the joint 

 (f.B.). 



In addition to the abov.e flexor there is a small 

 accessory flexor muscle on each side of the former. They 

 are probably comparable to the anterior flexor and lesser 

 posterior flexor of the corresponding segment of the chela. 



The muscles of the other segments of this limb are 

 very similar to those described above in the chela. The 

 two muscles of the dactylopodite, however, are extremely 

 small, and almost equal in size. 



XII. Second walking leg. 



The muscles here are similar to those of the first 

 walking leg. 



Goxopodite. The extensor arises from the sixth 

 pleural muscle chamber. The flexor arises from the sixth 

 sternal muscle chamber. 



In the Basi-ischiopodite both muscles arise from the 

 sixth sternal muscle chamber. 



XIII. Third walking leg. 



The muscles are similar to those of the two previous 

 appendages. 



Coxopodite. The extensor arises from the seventh 

 pleural muscle chamber. The flexor arises from the 

 seventh sternal muscle chamber. 



In the Basi-ischiopodite both muscles arise from the 

 seventh sternal muscle chamber. 



