HuTTON." On a New Gemis of Ralliclse. 109 



observations on it, but -vvitliout attempting any description, for doing wliich 

 I have not the requisite anatomical knowledge. 



The sternum (of which a front and side view, twice natural size, are given 

 on Plate XX., figs. 1, 2) is very small and quadrangular in shape, the breadth 

 being about '6 of the length, but constricted below the costal border ; the anterior 

 end is deeply concave between the articular grooves for the coracoids, which 

 are widely separated, and this concavity is smooth without any prominences 

 or median process. The only other birds that have this remarkable concave 

 outline of the anterior end of the sternum are, as far as I know, A2:)teryx, 

 Aptoi'nis, Didus, and, as Dr. Hector informs me, Notomis — all, it will be 

 noticed, except Ajjteryx being extinct forms. The costal border of the 

 sternixm only forms one fifth of the lateral border, and has articulations for 

 four sternal ribs only. The lateral processes are long and slender, commencing 

 not far below the costal border, and in a line with the apex of the keel ; they 

 are not dilated at the ends. The keel is so much reduced as to be almost 

 obsolete, as also is the furculum. The scapula makes a right angle with the 

 coracoid. The pelvis is somewhat similar in shape to that of Eallus pectorcdis, 

 but the ilia are not expanded anteriorly, and the pelvic disc is broader in 

 proportion behind, increasing in breadth regularly from the antacetabular 

 portion of the ilium. The posterior outlets of the neural canal are much 

 reduced, and the ilio-neural orifices quite obliterated. There are 9 dorsal and 

 12 cervical vertebrae. 



The following are some of the more important dimensions : — 



Inches. 

 Length of sternum to the coracoid groove ... ... "7 



Breadth 

 Height of keel 

 Length of femur 

 ,, humerus 



„ coracoid 



,, scapula 



•43 

 •1 

 1-2 



•95 

 •46 



•8 



Dr. Buller, in his Birds of New Zealand (p. 180), says that he has no 

 hesitation in considering my Rallus modestiis as the young of Kalhis 

 dieffenhachii ; but this is unquestionably a mistake. Both the birds obtained 

 by Mr. H. Travers were full-grown, one accompanied by her young one, and 

 the other containing well-developed ova ; they were both exactly alike in 

 colour and dimensions, in neither of which do they show any approach to the 

 colour and dimensions of R. dieffenhachii, as may be seen by comparing 

 descriptions of the two ; while in all known Bails the young soon acquire a 

 plumage appi'oaching in colour to that of the adult, and always attain tlieir 

 adult plumage before breeding. In its body, tail, wings, legs and feet, 



