116 PTERYLOGRAPHY. 



as in Gallus, Phasianus, and Argus, the dorsal tract of the Peacock differs very essentially from the 

 Gallinaceous type. It is linear and of equal breadth to behind the shoulder-blades (Plate VII, fig. 8), 

 but begins to widen in the pelvic region. Anteriorly, immediately behind the shoulder-blades, 

 there are beside it a few scattered contour-feathers. Consisting of three rows of feathers up to 

 this point, it receives the addition of a fourth row at the extremity of the shoulders, and then 

 increases by one feather in each transverse row upon the pelvis, thus forming a great saddle, 

 which covers the whole region of the rump to the tail. This saddle consists of from fifteen to 

 twenty transverse rows, of which the last seven are each sixteen feathers broad, the four preceding 

 ones twelve, and the six preceding these ten ; these are followed by some rows with nine, eight, 

 seven, six, and five feathers, which quite gradually effect the transition of the narrow spinal tract 

 into its wide hinder portion. It is only in the latter that the beautiful feathers of the male are 

 seated, and therefore this part in the female is much smaller, shorter, and weaker, although 

 similar in its arrangement. In the wing I counted from twenty-eight to thirty remiges ; the ten 

 primaries are graduated on both sides, so that the sixth is the longest ; the eleventh is very 

 small. In the male the tail contained twenty, or exceptionally nineteen feathers ; in the female 

 regularly only eighteen. The oil-gland is present, but concealed in the flesh up to the mamilla. 

 The contour-feathers exhibit no remarkable and sudden thickening at the lower extremity of the 

 shaft, and have a very small after-shaft ; in both these respects they resemble those of the Turkey. 



3. PENELOPID^:. 



\ 



i 



1. Crax. This genus has most resemblance to the Peacock in its pterylosis, and is distinguished 

 from it only by the circumstance that the dorsal tract is dilated even at the commencement of the 

 shoulder-blades, and then gradually becomes so broad that it is completely coalescent with the 

 lumbar tracts. The whole of this dilated portion is, however, sparsely feathered. In the inferior 

 tract the two main bands are separated as far as the anus, and the outer branch is narrower and 

 weaker. The contour-feathers are moderately thickened at the lower extremity of the shaft, and 

 have a very small after-shaft. The wings consist of twenty-four remiges, of which the 

 seventh is the longest, and the eleventh is not diminished. In the tail I counted twelve graduated 

 rectrices ; the oil-gland bears only a few small feathers on the mamilla. I examined Crax alector 

 and C. MumenbacJdi, which agreed in all respects. 



2. Penelope. I have only been able to examine two species, namely, P. jacutinga and 

 P. superciliaris. The latter agrees exactly with Crax ; in the former, however, there is a narrow 

 space in front, between the shoulder-blades, in the generally diffused dorsal tract, which covers 

 the whole of the back ; this is enclosed by the tolerably strong limbs of the scapular fork, and 

 reaches but a short distance into the hinder part. In the inferior tract I could find no difference 

 from Crax in either species, and hence it would appear that the complete separation of the two 

 main stems as far as the anus is common to all the Penelopidte. Nevertheless, in P. jacutinga 

 they were united to each other by a transverse band immediately in front of the anus. In this 

 species a few very widely scattered contour-feathers stand near the main bands on the outside ; 

 and I was particularly struck by the enormous thickening of the lower part of the main stem of 

 its contour-feathers, which occupies two thirds of the whole length of the shaft. This part is 



