460 



STRUCTURE AND CLASSIFICATION OF BIRDS 



Tachyeres, are hardly if at all to be distinguished anatomically 

 from the typical geese and ducks. Our knowledge of the 

 muscular structure of this group of birds is mainly due to 

 FUEBEINGEE, who has illustrated the fore half of the body 

 by two double plates referring to Anser cinereus. 



An interesting duck character (also, however, found in 

 Colymbus, Tinami, and some Galli) is the meeting of the two 

 great pectoral muscles over the carina sterni. In Mcrgus 



FIG. 217 BICEPS FEMOKIS OF DUCK (Hi), TO SHOW ITS 

 RELATIONS TO GASTROCNEMIUS (AFTEH WELDOX). 



mergaiixcr, for example, they blend for a space of half 

 an inch. 



There is a biceps slip present, 1 and this has at least 

 sometimes a peculiar arrangement, which is remarkably like 

 that of the Colymbi. In Anser cinereus FURBRINGER 

 figures the biceps slip as attached in the ordinary way to 

 the tendon of the tensor patagii longus ; but before it is thus 

 attached it gives off a slender tendon, which exactly as in 

 the Colymbi runs over the patagium and is inserted on to 

 the fore arm in front of the broad and diffuse tensor patagii 

 brevis tendon. 



In Anas FURBRINGER figures this tendon as joining the 



1 Not in Cygnus Bciciclii. 



