OCR Text |
Show 606 ON THE AN ATOM! OF THE KINGFISHERS. [May 19, are which have it not. The expansor secundariorum is another nmscle which is sometimes absent and sometimes present. In marked contrast to the muscular anatomy (excepting the leg-muscles, of which the formula seems to be always A X - ) , and to the external characters, is the syrinx. I have examined this organ in Alcedo, Bacelo, Cittura, Ceryle, Halcyon, and Sauropatis, find it to be most uniform in structure. In all it is of the typical tracheo-bronchial form, without, a complete coalescence of the last rings of the trachea, except sometimes in front. The intrinsic muscles (a single pair) are well developed and fan out considerably at their insertion onto the first, or apparently sometimes the first and second bronchial semirings. In Bacelo cervina it is quite plain that there are two pairs of intrinsic muscles. The most anterior of these is the more slender; tbe wider muscle arises from the trachea just where the extrinsic muscles are given off; it covers over the insertion of the first muscle and is pyramidal in form, the first muscle being an elongated strip arising in common with the extrinsic muscle. The Kingfishers being a group which shows so much diversity in structure, the following tabular statement may be of use:- Bacelo Tanysiptera . Syma Cittura Alcedo Pelargopsis . Todirhamphus Alcyone Ceryle Halcyon Sauropatis Sauromarptis Exp. sec. + + + + 0 + + + + 5th Bemex. - ... + + - + Tensor pat. brev. 2 tendons -f- ant. slip. n n 2 tendons ; no ant. slip. 2 tendons + ant. slip. 1 tendon. 2 tendons -j- ant. slip. n ii 1 tendon. 1 tendon + ant. slip. »» )> 2 tendons -j- ant. slip. Biventer link. + + + Oil-gland. tufted. nude. nude. tufted. tufted. tufted. tufted. 1 + in one of two specimens of S. vagans. The above table not only displays the variation in structure the family but shows the impossibility of a subdivision of the family, at least without further facts-for it is unnecessary to point out specially the lacunae in the above table. Halcyon is perhaps to be regarded as the simplest form, while Bacelo and Sauropatis are at the opposite extreme. The necessary separation of Sauropatis and Halcyon is the classificatory fact upon which I w'ould lay the greatest stress. It may be that the black-billed species will turn out to be Sauropatis, and the red-billed the true Halcyon. I would also point out the somewhat disappointing fact that no particular results seem to be obtainable from a comparison of the quintocubital with the aquintocubital genera. |