1890.] THE STRUCTURE OF PSOPHIA. 339 



])ositioii iimoiig Schizogiiatlious birds ; and I inaiiitaiu that the struc- 

 ture of the skull is at least not opposed to such a conclusion. 



In I'sophia the omentum is very much icduced and the gizzard is 

 attached to the ])arietes 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 es])ecially resembles Cariama and C/iunr/u 

 and the Rallidse, and differs in the most pronounced fashion from the 

 Gruidse. I liave not yet dissected many Limicolee from this point 

 of view ; but in Htematopus ostralegus the disposition of the 

 omentum is more like that of tlie Cranes, though it is more reduced 

 than in that grouj). 



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 Limicolse, 

 though it is connected with this family by OiJdicnemus, which should, 

 in my o])inion, be removed from the Limicolse. 



The Limicolse may, from their skull-characters, be thus de6ned :— 



Schizorhinal birds with the maxillary jirocess of the nasal directed 

 forwards. Supraorbital margin with a shar]) 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 sej)tum 

 largely unossified. Lachrymal and prefrontal process of ethmoid 

 fused to form a com])lete ring of bone. Maxillo-j)alatines very small 

 and fused with ])aiatines, invisibly or nearly so from beneath. Post- 

 orbital angle aud ])ostfrontal process distinct ; temporal fossa com- 

 mencing behind former process and visible on the occipital surface of 

 skull. Basipterygoid ])roccsses 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 jjointed in front. Palatines 

 narrow in front, wide behind ; maxillo-palatines large and swollen, 

 quite conspicuous from below. Lachrymals quite free from pre- 

 frontal process' of ethmoid. Interorbital sej)tum incompletely ossified. 

 Articulation of quadrate covered by a descending process of squa- 

 mosal. No postorbital angle ; temporal fossae just reach the occipital 

 face of skull. No basipterygoid jirocesses. 



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 — 

 Charadriomorphos and Geranomcrphsc ; but a consideration of other 

 forms, including Psopliia, appears to me to render this arrangement 

 impossible. 



The Cranes themselves are the first stumbling-block. They 

 agree with the Limicolse in many, perhaps most, characters, but in 

 others they agree with the Rallidse. 



' ■• On the Olassificatiou ofBii-ds, &c.," P. Z. S. 1867, \>. 457. 



