246 OSTEOLOGY OF ANSERES. 



ii, mi of the bronchi. This is of ;i very unique shape in Glaucionetta, 

 and 1 have figured a specimen of it as it occurs in this Duck in Couc-s's 

 •• Key," showing the development from behind (second edition, Pig. 98). 



It is my intention, on some future occasion, to make a thorough com- 

 parison of these tracheal caskets as they are found in our American 

 Auseres, continuing the labors of Garrod and Yarrell in that direction. 



Anseres always have the extremities powerfully developed, and in 

 consequence we find strong- skeletal supports for their pectoral and pel- 

 vic limbs. The bones that enter into them, however, rarely offer any- 

 thing peculiar or make any marked departures from the average type 

 of the skeleton of the parts in Aves. 



In Figs. 27 ami 34 of Goues's Key I offer drawings of the pectoral 

 and pelvic limbs of Glaucionetta islandica, and they give a very good 

 idea of these bones as they occur among the Ducks generally. It must 

 be noted, however, that in Fig. 27 (of the "Key") another small joint 

 must be added at I), in order to perfect the limb. This part of the 

 skeleton in Glaucionetta is completely non-pneumatic; not the case with 

 many other Ducks. 



It must likewise be observed that in Fig. 34 the patella is not shown, 

 whereas 1 believe this fowl possesses one in common with other Ducks. 



Professor Cones lettered these two drawings of mine himself, and by 

 an oversight has made in Fig. 34 am. point to one of the trochlear of 

 tarso- metatarsus instead of the accessory metatarsal. 



Olor, the Teals, and the Spoon-bill all have a perfectly pneumatic 

 humerus, the foramina being found at their usual site. 



In the last-named species this bone is considerably longer than the 

 non-pneumatic ulna and radius. Its radial crest is rather low and short, 

 while the ulnar one curls conspicuously over the pneumatic fossa. Be- 

 tween this latter and the humeral head a deep notch, or rather groove, 

 is found. 



The shaft is of a glistening whiteness, and composed of a wonderfully 

 compact tissue, and shows scarcely any curve along its continuity. 

 The distal extremity presents the usual characters, the oblique and ul- 

 nar tubercle on the radial side and a broad passage for the teudouson 

 the other. 



Along the shaft of the ulna we notice a faintly' pronounced row of pa- 

 pilla- for the secondary quill-butts, a longitudinal muscular line marking 

 the opposite side. This bone is considerably bowed along its proximal 

 third, while, on the other hand, the radius is nearly straight. The two 

 carpal elements which remain free throughout life in Aves generally 

 are here present, and of a comparatively large size. Ulnare in most 

 Ducks, and less so in the Swan, shows a strongly-defined groove down 

 its ancouaj aspect for the lodgment of the tendon which there passes. 



Carpo- metacarpus presents the usual form, and its main shaft is more 

 than two-thirds as long as the radius. There are two phalanges in pol- 

 lex digit, as there are three in index, the blade of the proximal joint of 



