GRALLATORES. 323 



its colouring, particularly in the azure-blue of the throat and 

 chest, a character by which it is readily distinguished. 



The Azure-breasted Porphyrio is abundant at Swan River, 

 inhabiting the thick reed-beds and swampy districts of the 

 lakes and rivers round Perth and Freemantle. Its habits and 

 economy so nearly resemble those of the Porjjhj/rio melanotus 

 of Tasmania and New South Wales, that the description of 

 one equally applies to the other, and therefore need not be 

 repeated here. 



The gizzard is strong and muscular, and the food consists 

 of vegetable substances, aquatic insects, and mollusca. 



The only difference observable between the sexes is, that the 

 male is rather brighter in colour and somewhat larger in size. 



Occiput and crown of the head blackish brown, gradually 

 passing into the light violet-purple which spreads over the 

 nape, flanks, and abdomen ; throat, cheeks, fore part of the 

 neck and breast light azm*e-blue ; all the upper surface from 

 the nape downwards, including the tail, deep chocolate-brown ; 

 shoulders and spurious wing azure-blue ; primaries blackish 

 brown, their outer webs strongly tinged with green ; irides 

 bright red ; bill red ; knees, lower part of the tarsi, and inside 

 of the feet dark greenish grey ; remainder of the legs and feet 

 grass-green. 



Total length 18 inches ; bill If; wing 10^ ; tail 4^ ; tarsi 3^. 



Genus TRIBONYX, Du Bus. 



The habits and economy of the two known species of this 

 genus differ so much from those of the Gallinules that no 

 ornithologist can question the propriety of their separation. 

 As their longer tarsi and shorter toes would indicate, they are 

 more terrestrial than the members of the genus Forphyrio, 

 and accordingly we find that they wander over the plains and 

 open pasture lands, instead of keeping to the water or the 

 sedgy portions of river-sides. 



Y 2 



