C. J. Sundevall on the Wings of Birds. 415 



This is due not only to tlie greater length of the remiges 

 in the Song-birds, but really also to the greater length of 

 the coverts in proportion to the body in the other orders, 

 which distinctly shows that in the Raptorial birds, Ardece, 

 Ciconiae, and all other birds of which the cubital remiges are 

 comparatively of the same length as those of the Song- 

 birds, the coverts reach beyond their middle. Cinclus, 

 which has shorter cubital remiges than other Song-birds, 

 nevertheless retains the proportions of that order, and a direct 

 comparison between nearly equally large, and in other respects 

 similar, species shows it distinctly, e. g. Hirundo, Turdus, 

 Corvus, compared with Cypselus,Cuculus, Coracias (see fig. 10, 

 Turdus, fig. 11, Cuculus). In some Water-birds and small 

 Waders the great cubital coverts are but little shorter than 

 the remiges ; in other respects they present many peculiarities, 

 e.g. in Gallus ! 



If this diff'erence in the size of the coverts be taken to- 

 gether with the diff'erence which will be mentioned below 

 (under § 3), it is the most easily recognizable and most 

 general of all the external characters at present known by 

 which the Song-birds are differentiated from the other orders. 

 2. Tectrices secimda seriei (the coverts of the second 

 row, m, n), which lie immediately upon the greater coverts, 

 generally resemble the ordinary feathers of the body. Those 

 which belong to the cubitus have usually the peculiarity 

 of lying reversed with relation to the greater coverts and 

 the remiges, so that the inner margin of each feather 

 (that turned towards the humerus) is free and covers the 

 outer margin of the next one. But I have always found 

 them unreversed in Trochilus, Coracias, Cuculus, Columba, 

 Gallus, Lestris, Larus, Sterna, and Uria, as well as in young 

 Song-birds in their first dress*. They are inserted in 

 the skin either immediately behind the muscular layer, 



* Mr. W. V. Wright has kindly communicated to me the observation 

 made by him, that some of those which lie far back on the cubitus, 

 together with the corresponding feathers of the next series (§ 3), resume 

 tlie right position (like the remiges) in all Gallinse and Water-birds (see 

 fig. 3, n, n). 



