Page:The Fauna of British India, including Ceylon and Burma (Birds Vol 3).djvu/9

Rh apteria), the presence or absence of an aftershaft on the body-feathers,, the occurrence of down, the presence or absence of a uropygial oil-gland, and its being tufted, i. e. partially surrounded by a circlet of feathers, or naked, and the number of remiges and rectrices, are amongst the points of importance. Latterly, since the late Mr. R. S. Wray, in the ' Proceedings of the Zoological Society ' for 1887, showed that, in several orders, the fifth secondary quill or cubital, counting from the distal extremity of the ulna, is wanting, some importance has been attached to the fact, and those birds have been termed quincubital which retain the remex in question, whilst those forms in which it is absent are dis- tinguished as aquincubital.

Most of the terms employed are easily understood, but four diagrams are added for the explanation of the names applied to the bones of the palate and the muscles of the thigh. The two figures illustrative of the former, which are used by permission of their author, the late Professor Huxley, and are taken from his classical paper in the f Proceedings of the Zoological Society' for 1867, serve to explain the two most important types of palatal structure in carinate birds the " schizognathous " and " desmognathous."" In the des- mognathous palate the maxillo-palatines are united across the median line, and the vomer is either small and slender or rudimentary. In schizognathous skulls the maxillo-palatines are usually elongate and lamellar and do not unite either with the vomer or with each other. In both the vomer, if present, is pointed in front, not broadly truncated as in the segithognathous type, represented by the Raven (Vol. I. p. 4) . There are other distinctions in these three types of bony palate, but those mentioned are the most conspicuous. The fourth principal type, the dromaeognathous, is not found in any Indian birds.

The muscles of the thigh are shown in the two figures taken from the works of Garrod and Forbes, the former of whom attached great importance to them as evidence of affinity. The ' ambiens ' muscle was regarded by him as affording a clue to the whole system, and by means of it he divided all Carinate birds into Homalogonatse, in which the muscle (with a few aberrant exceptions) was present, and the Anomalogonatse, in which it was absent. The other thigh-muscles, to the presence or absence of which he attached importance, were the femoro-caudal, accessory femoro- caudal, semitendinosus, and accessory semitendinosus.