254 THE MYOLOGY OF THE RAVEN. 



and the other, smaller, from the back of the head of the 

 fibula. In the Corvidae there is a well-developed third 

 head, which comes off from above the fibular notch of the 

 outer condyle of the femur, and in these birds, too, there is 

 no fibular head to this muscle, but two tibial ones instead. 

 Geococcyx agrees, however, with most birds in having 

 this muscle attached nearly the whole length of the 

 posterior aspect of the shaft of the tibia by lightly 

 attached carneous fibres. 



" About a centimetre above the tibial cartilao^e it 

 terminates in a strong subcompressed tendon, which, 

 passing beneath the cartilage referred to, crosses the 

 ankle-joint in front of all the other fiexor tendons, and 

 then passes through the inner of the two longitudinal 

 perforations of the hypotarsal apophysis of the tarso- 

 metatarsus. Down the posterior aspect of the shaft of 

 this bone the tendon still maintains its anterior position 

 and exhibits a predisposition to ossify. But this does not 

 actually take place in the specimen before me. Above 

 the distal trochleso, it makes the fibrous connection with 

 the tendon of the fiexor longns haUueis already described. 

 Once within the limits of the post-trochlear space, the ten- 

 don of this muscle behaves in a manner common to most 

 birds — that is, it quadrifurcates, and each branch takes 

 a course close up to the joints on their plantar aspects, 

 and running through the slits in the perforated tendons 

 pass in each case to the ends of the toes, where they 

 become attached or inserted upon the infero -proximal 

 tubercles of the ungual phalanges. The one passing 

 along under the fourth digit sends up a slip which is 

 attached to the under side of the shaft of the prebasal 

 joint, thus making good the deficiency here for what 

 is represented in the other toes by an independent 

 tendon. 



