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Show 1876.] MR. A. H. GARROD ON THE ANATOMY OF COLIUS. 419 PICIFORMES. PASSERIFORMES. With tufted oil-gland and With nude oil-gland and without caeca. with caeca. f Pici. Passeres. < Capitonina. Bucconida (? as to caeca). (Ramphastina. Trogonida. Upupida. Meropida. (Coliida). Galbulida. Bucerotida. Caprimulgida. Alcedinida. f Coraciida. \ Momotida. From what has been said above it is evident that Colius must be included among the Piciformes, and near those of this division with a left carotid only, a four-notched sternum, and a blended plantar-tendon arrangement. No other piciform bird, however, combines all these characters. In the Alcedinidae the sternum and plantar arrangement correspond ; in the Bucerotidae Toccus agrees as to the carotid and the plantar tendons. The Picidae (Picinse + Capitoninae -f- Ramphastinae) have a left carotid, a two-notched sternum, but a specialized plantar-tendon distribution. Consequently the fact that the combination of characters is unique justifies us in retaining the Co-liidae in a separate family, related on the one hand to the Picidae, and on the other to the Alcedinidae and Bucerotidae. Something must be said with reference to the probability of Colius having psittacine affinities. It is an interesting fact that in those species of the genus Cacatua (galerita, leadbeateri, moluccensis, &c.) in which the oil-gland is not lost, the resemblances (only accidental I assume) to the genus Colius are peculiarly numerous. In these Cacatua there is a left carotid artery only, no ambiens muscle, and a myological formula A,XY. Nevertheless I hope that in m y paper on the Order Psittaci * the impression left by its perusal is that the Parrots all sprang straight away from a stock with two carotids and an ambiens muscle. Such being the case, and Colius most certainly not being a true Parrot, the arguments in favour of its having arisen independently from the psittacine ancestor, and of its having undergone (also independently) cacatuiform modifications during the progress of its evolution, are less easy to accept than those which suppose it to have sprung, as I have above assumed, from the less specialized stock whence has been derived all the Anomalogonatee. The form of the sternum and the distribution of the plantar tendons are in favour of this view of the question. lt may be mentioned that the syrinx of Colius (which has been figured by Johannes Miillert in a closely allied species) is most nearly related to that of Ceryle among the Kingfishers. * P. Z. S. 1874, p. 586. t Ueber die bisher unbekannten typischen Verschiedenheiten der Stimmen« organe der Passerinen, 1847, pl. v. figs. 9-12. |
