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Show 1890.] THE STRUCTURE OF PSOPHIA. 339 position among Schizognathous birds ; and I maintain that the structure of the skull is at least not opposed to such a conclusion. In Psophia the omentum is very much reduced and the gizzard is attached to the parietes by an almost vertically running sheet of membrane; the elongated sternum completely covers the lobes of the liver, and the gizzard itself only just reaches beyond it. In these particulars Psophia especially resembles Cariama and Chung a and the Rallidae, and differs in the most pronounced fashion from the Gruidae. I have not yet dissected many Limicolae from this point of view; but in Hamatopus ostralegus the disposition of the omentum is more like that of the Cranes, though it is more reduced than in that group. The above comparison of Psophia with other forms shows that it cannot be closely united with any other genus of those referred to. It appears to me to be most widely removed from the Limicolae, though it is connected with this family by CEdicnemus, which should, in m y opinion, be removed from the Limicolae. The Limicolae may, from their skull-characters, be thus defined :- Schizorhinal birds with the maxillary process of the nasal directed forwards. Supraorbital margin with a sharp edge marked above by considerable furrows for the nasal glands. Foramen magnum on the under surface of the skull; occipital foramina present. Vomer truncated or ending in a concave margin. Interorbital septum largely7 unossified. Lachrymal and prefrontal process of ethmoid fused to form a complete ring of bone. Maxillo-palatines very small and fused with palatines, invisibly or nearly so from beneath. Postorbital angle aud postfrontal process distinct ; temporal fossa commencing behind former process and visible on the occipital surface of skull. Basipterygoid processes usually present. The family Rallidae shows the following characters :- Holorhinal birds with the maxillary process of the nasal facing outwards. Supraorbital margin rounded and without depressions for nasal glands. Foramen magnum on the posterior face of the skull; no occipital foramina. Vomer pointed in front. Palatines narrow in front, wide behind ; maxillo-palatines large and swollen, quite conspicuous from below. Lachrymals quite free from prefrontal process of ethmoid. Interorbital septum incompletely ossified. Articulation of quadrate covered by a descending process of squamosal. No postorbital angle ; temporal fossae just reach the occipital face of skull. No basipterygoid processes. If the members of these two families were the only " Gralline " birds known, it is obvious that there would be no difficulty in accepting Prof. Huxley's * arrangement of them into two sections- Charadriomorphae and Geranomcrphae ; but a consideration of other forms, including Psophia, appears to m e to render this arrangement impossible. The Cranes themselves are the first stumbling-block. They agree with the Limicolae in many, perhaps most, characters, but in others they agree with the Rallidae. 1 " O n the Classification of Birds, &c," P. Z. S. 1867, p. 457. |