427 
C. J. Sundevall on the Wings of Birds. 
subsequently they have been called pallium &c. 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 Yet.-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 Song¬ 
bird, w r e 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, b q), 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 Gallinse, diurnal 
Baptores, Psittacus, and Columba show the same characters. 
The nocturnal Baptores (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 
