OCR Text |
Show 1885.] MR. F. E. BEDDARD ON THE CUCKOOS. 179 inferior tract again divides, and each half is continued on either side of the sternal carina, narrowing gradually, until the termination, a little way in front of the cloaca; on either side a branch two feathers wide is given off to the humeral tract and another of the same width to the row of feathers which occupies the anterior portion of the patagium ; the inferior tract of either side has no outer branch ; and the disposition of the whole tract is therefore similar to that of Cuculus and Piaya, more especially the latter. The spinal tract is narrow and very closely feathered upon the neck ; it bifurcates into two narrow, also closely feathered tracts at the junction of the neck with the body ; the rest of the spinal tract is separated by a distinct break from the anterior portion, and considerably wider, and at the same time less closely feathered upon the lumbar region, where it is continuous with the femoral tract j on a level with the articulation of the femora the two halves of the spinal tract reunite and run as far back as the base of the oil-gland as a single closely-feathered tract. Diplopterus navius.-I have only been able to examine one example of this Cuckoo, but, so far as I could make out from that example, the pterylosis agrees fairly closely with that of the Cuculine forms, as it might be expected to do from the structure of the syrinx ; I do not, however, feel able to speak at all positively upon the subject. Geococcyx.-Of this genus I have been able to examine Geococcyx affinis, and another species not named ; it does not present any differences from G. affinis. The ventral tract commences from the point of junction of the two rami of the lower jaw, and at first only occupies the extreme middle of the area of stem uniting the mandibles ; further back it becomes wider; on the neck the feathers have the characteristic arrangement already referred to under the description of Centropus. The ventral tract, after giving off a single row of feathers to the hyposternum, divides as usual: the inner broader limb is two feathers wide, the outer is a single row of feathers ; they do not reunite posteriorly. The spinal tract increases in strength, but decreases in width, towards the junction of the neck with the trunk ; as in other species (e. g. Centropus) there is a complete, or an almost complete, break between the cervical portion of the spinal tract and its two posterior halves ; furthermore the anterior portion of the tract does not bifurcate posteriorly, but ends abruptly between the shoulder-blades, being at this point two feathers wide. The spinal tract is not connected with the humeral tract, there is a completely nude space between them. The two halves of the posterior section of the spinal tract are separated by a considerable break from the cervical section; at first each is formed of a very few scattered feathers, but the feathering soon gets stronger ; at about the level of the attachment of the femora the two halves of the spinal tract unite. The femoral tract is very distinct in this Cuckoo, more so than in any species which I have examined: instead of a diffuse feathering over the whole upper surface of the thigh, the feathers are mainly |