C. J. Suudevall on the Wings of Birds. 427 



subsequently they have been called pallium Sec. They are 

 very different in number and size, for which reason they 

 often furnish good generic and family characters. As an 

 example we need only cite the division of the genera of 

 Alcedines, which I have already made in the Vet. -Acad. 

 Handl. 1835. Those which live on the Old Continent 

 [Halcyon, Alcedo, &c.) have such large scapular feathers 

 that they quite cover the usually shining blue hinder part of 

 the back. The genus Ceryle, Boie, which includes the 

 American species, and Alcedo rudis on the Old Continent, 

 is chiefly distinguished by its short scapular feathers, which, 

 as in the Song-birds in general, do not seem to be differ- 

 entiated from the dorsal feathers, although they form, ap- 

 parently always, a series widely separated from the latter. 



Third Chapter. 



On the Muscles and Dermal Surface of the Arm. 

 If the feathers be removed from the cubitus of a Sons'- 

 bird, we find on its under surface a very deep and narrow 

 pit of half the length of the cubitus (which we may call the 

 sinus cutaneus postulnaris, fig, 9, bq), produced by the skin 

 being folded in between the ulna {b) and the sinew of the 

 muse, flexor carpi radialis [q q), which latter lies transversely 

 upon the underside of all the remiges of the arm, and also 

 externally in front of the true arm. Near this we see 

 another, shallower, but generally somewhat broader pit (bs), 

 between the ulna and the radius, and in both are situated 

 some down or rudimentary feathers. These pits are deficient 

 in all Water-birds and Waders, in which the arm at this 

 point is flat and even. In many forms of these two orders 

 (e. g. Carbo, Sterna, Ciconia) there is an inconsiderable im- 

 pression in place of the pit between the radius and ulna, but 

 of the true sinus no trace occurs. The Gallinge, diurnal 

 Uaptores, Psittacus, and Columba show the same characters. 

 The nocturnal Raptores (e. g. Strix liturata and S. lapponica) 

 have the pit between the radius and ulna very large and deep, 

 but no sign of the sinus behind the ulna. In Cypselus there 



