TURN ICES 821 



chiefly due to PARKER, 1 who has described in detail the 

 entire skeleton of Hemipodius varius, and also the skull of 

 Ticrnix rostrata. The atlas is perforated for the odontoid. 

 There are 15 cervical vcrtcbrcc, of which Nos. 10-15 bear 

 haemapophyses. None of the dorsals are ankylosed. The 

 sternum is reached by three or four ribs, and has one pair of 

 deep lateral incisions cutting off two long thin postero- 

 lateral processes. 



The skull is aegithognathous in its vomer, broad in front, 

 and double posteriorly, and in the slender hook-like maxillo- 

 palatines ; the latter, however, are not unlike those of many 

 gallinaceous birds, while HUXLEY has compared the vomer 

 with that of Tetrao urogallus. The nostrils are pseudo- 

 holorhinal, and, as in pigeons, there is a considerable alinasal 

 ossification, reducing the long nares, which are perfectly 

 pervious. As is also the case with the pigeons, the ecteth- 

 moids are large and solid, and have fused with the lacrymals. 

 There are well-marked basipterygoid processes. 



RALLI 



Definition. Aftershaft usually present. Carotids, two. Muscle 

 formula of leg, ABX(Y) + . Expansor secundariorum always 

 present. Tensor patagii brevi3 without recurrent slip to tensor 

 patagii longus. Caeca long. Skull schizognathous and holo- 

 rhinal. 



The rails are a group of birds of very uniform structure. 

 They have as a rule a tufted oil gland, but Porzana Carolina, 

 is an exception. The aftershaft is present. The rectrices 

 vary in number from 10 (Aramides cay omens is) through 12 

 (Porzana Carolina} to 14 (Ocydrmnt/x Earlei). 



The spinal tract encloses a long narrow apterion, which 

 commences earlier in Rail its aquaticns than in Fulica atra. 

 The latter bird has almost a gap between the anterior and 

 posterior parts of the spinal tracts. The pectoral tract of 



1 In his papers on the osteology of gallinaceous birds and of the scgitho- 

 gnathous skull in Zool. Trans, vols. v. ix. x. 



Y 



