52 PTERYLOGRAPHY. 



with an ascending point near the occiput, forming no ruff, and apparently divided anteriorly 

 beneath only by a continuation of the inferior space j 1 feathers generally sparse ; cervical and 

 scapular portions of the spinal tract exactly as in C. papa, as also the somewhat broader dorsal 

 portion, which is triserial posteriorly. Lateral neck-space short, but perceptible. The femoral 

 tracts pass into the crural tracts. Inferior tract very broad, but sparsely feathered, with a small 

 insular space on the pectoral muscles ; outer branch anteriorly very broad, broader than usual. 

 Remiges only twenty-three, or at the outside twenty-five in number ; but ten of these are still on 

 the hand. Tail not rounded as in the other species, but abruptly truncated ; the middle feathers 

 are, consequently, somewhat abbreviated. Oil-gland quite naked. 



All these four species are described from skins in the collection at Halle ; the second was 

 also examined in a fresh state. 



C. FALCONS. 

 FALCO, Linn. 



This group, which includes so many species, and is so readily and certainly characterised by 

 the structure of the beak and feet, has no single, equally general and exclusive pterylographic 

 character ; for although in most Falcons the inferior tract possesses a freely diverging external 

 lateral branch, which, if it were only universal, would clearly distinguish them from the Vultures 

 both of the Old World and of America, there are, according to my observations, two exceptions 

 to this rule, as both in Falco haliaetus (Plate II, fig. 7) and in F. ecaudatus DAUD. we find a 

 simple, generally enlarged pectoral tract, in which respect these two Falcons agree perfectly with 

 the Old- World Vultures. Still, notwithstanding this great similarity, a pterylographic difference 

 between them and the Vultures may be demonstrated ; namely, that in the latter the jugular 

 portion of the inferior tract is completely separated by a space from the pectoral portion, whilst in 

 the Falcons referred to the two parts are connected and pass into each other. This union of the two 

 tracts is, indeed, proper to all the Falcons, but is not always so distinct and perfect. The jugular 

 portion of the inferior tract forms an inner branch at its lower extremity just before the furcula, 

 which passes down along the furcula to its lowest part, and there terminates ; this is wanting only 

 in Pcmdion and Rhynchodon. This branch is frequently very short, but is, notwithstanding, 

 recognisable from the fact that the inferior tract itself is diminished immediately behind the 

 branch, and then consists only of a single row of feathers, which is continued over the furcula, 

 and effects the union of the jugular with the pectoral portion. If it were altogether wanting 

 (which, however, I have never found to be the case), there would be a complete approximation to 

 Gypaetos, if at the same time the outer branch of the pectoral portion were coalescent with the 

 main stem ; but, as far as I know, this case never occurs, and the above-mentioned mode of 

 union, together with the undivided condition of the pectoral band of the inferior tract, always 

 constitutes a characteristic distinction of the Falcons. As, moreover, the jugular portion of the 



1 As the skin of the only specimen examined by me had been cut longitudinally beneath, it did not 

 allow the extent of the inferior space to be determined accurately. 



