442 C. J. Sundevall on the Wings of Birds. 



on the cubitus in all the musculi digitorum et carpi except the 

 flexor carpi ulnaris. 



As the result of this exposition it appears that all these 

 birds, notwithstanding their very considerable differences, 

 agree in the general structure of the muscles of the cubitus, 

 and only seem to present occasional differences, owing to 

 which the orders are difficult to characterize. 



The Gallinse, however, appear to show definite peculiarities, 

 namely : — (a) the iyfohumero -ulnar es are unusually developed : 

 the inner one, which is almost peculiar to tliera, extends to 

 I, and the outer one to the apex of the ulna ; [b) the flexor 

 digitorum sublimis is unusually small and shifted outwards ; 

 (c) the extensor indicis projirius commences far down (which, 

 however, is also the case in Ciconia). 



The other orders seem to vary more ; but they nevertheless 

 distinctly group themselves around the Gallinse, and very 

 closely resemble each other. From the few well-known ex- 

 amples they are difficult to characterize; but it must be re- 

 marked that the Eaptorial birds known to me have cylindrical 

 sinews to the most anterior muscles, a shorter pronator supe- 

 rior, a broader extensor digitorum communis, &c. 



The Waders have a weak extensor carpi ulnaris, wdiich com- 

 mences upon the humero-ulnaris externus, but they vary much. 

 The Water-birds have a very small extensor carpi radialis 

 brevis and deltoideus, but present three quite different forms : 

 Sterna and the Ducks with a more ordinary external form, 

 the latter with a small separate humero-uhiaris interior ; and 

 the Pygopodes with the wings much flattened, and, in con- 

 sequence, an unusual appearance of the muscles and an 

 unusual position of the pronatores ; the supinator lies only 

 on the outer side, the fascia ulnaris is closely attached to the 

 ulna without any interspace, &c. 



I can least of all pronounce an opinion upon the Coccyges, 

 as only a few of the more aberrant forms of that order are 

 known to me, and at present I have no opportunity of 

 making up this deficiency. They seem, however, nearly to 

 approach the Accipitres. 



