60 PTERYLOGRAPHY. 



is the greater breadth of the exterior branch, which also contains stronger feathers. With regard 

 to the dorsal portion of the spinal tract, it is to be remarked that between it and the fork of the 

 scapular portion some scattered contour-feathers are to be perceived, which are more numerous, 

 and consequently placed closer together, in the Sea Eagles. This arrangement forms, as it were 

 a transition from that occurring in F. melanops and F. anthracinus, to that of the ordinary Falcons 

 with two divergent rows -of feathers. The tipper surface of F. apivorus is represented in Plate 

 II, fig. 4. There are twenty-seven remiges ; the first five with the usual angular emarginations, 

 of which a trace is still visible on the sixth. The first primary perceptibly abbreviated, as long 

 as the eighth ; the second somewhat shorter than the sixth ; the third nearly equal to the fourth 

 and fifth, but the fourth really a little longer than either of the other two. 



2. F. chrysaiitos seu imperialis. In all respects like the preceding, except that the first 

 primary is longer than the eighth, and but little shorter than the seventh. 



3. F. navius. The first six remiges with an angular emargination, which is but slight on 

 the sixth; first primary longer than the eighth. 



4. F. ditcalis LIGHT. (F. Bonettii TEMM., PL Col., 288) First primary of the same length 

 as the eighth, fourth longest ; first five with a strong emargination of the inner half of the vane, 

 placed far down the feather. 



5. F. pennatm TEMM., PI. Col., 33. First five primaries with a considerable emargination : 

 first as long as the eighth ; second as long as the sixth ; third equal to the fifth ; fourth but little 

 longer than the latter. 



b. With naked tarsi. 



In the Eagles of this section the whole plumage is closer ; the external branch of the pectoral 

 portion of the inferior tract is only half free, and is united at its apex by a hook to the hypopterum. 

 The dorsal part of the spinal tract is also longen and scarcely separated from the scapular 

 portion. 



1. F. leucocephalus BUFFON, PL Enlum., 411. Remiges somewhat imperfect, but the first 

 as long as the seventh, the third equal to the fifth, and the fourth a little longer than the latter. 



2. F. albicilla. In all twenty-seven remiges : first five with an emargination situated far 

 down, of which a trace is perceptible also on the sixth ; first primary as long as the eighth ; 

 second longer than the seventh ; the fifth the longest, but the third, fourth, and sixth only a 

 little shorter. 



3. F. brachydactylus. Likewise with twenty-seven remiges : first five with a very strong 

 angular emargination on the inner vane, situated low down on the first, but gradually ascending 

 on the following feathers. First primary scarcely so long as the seventh, second longer than the 

 sixth, and the third (in two of the specimens examined by me) the longest. 



4. F. macei TEMM., PI. Col., 8 & 223. Twenty-seven remiges : the first five with an 

 emargination situated very low down. First primary scarcely so long as the eighth, second longer 

 than the seventh, third and fifth of equal length, fourth as much longer as the sixth is shorter than 

 the fifth. 



