proposed Classification of Birds. 87 



centres; the axes of the scapula and coracoid have the same 

 general direction ; certain of the cranial bones have characters 

 very unlike those possessed by the next order — the vomer for 

 instance being broad posteriorly, and generally intervening be- 

 tween the basisphenoidal rostrum and the palatals * and ptery- 

 goids; the barbs of the feathers are disconnected; there is no 

 inferior larynx ; and the diaphragm is better developed than in 

 other bu'ds. 



The Ratitce are divided into five groups : the first contains 

 the genus Striithio, the second Rhea, the third Casuarius and 

 Dromceus, the fourth the Dinornithidae, and the fifth the Apterij- 

 gidce. These five groups are separated by very trenchant cha- 

 racters, principally osteological, afforded not only by the cranial 

 bones, but by many parts of the skeleton. 



The Carinat.e comprehend all other existing birds. The 

 sternum possesses more or less of a keel, and ossifies, except 

 possibly in the genus Strigops, from a median centre as well as 

 from lateral paired centres. The axes of the scapula and cora- 

 coid meet at an acute, or, as in Didus and Ocydromus, at a 

 slightly obtuse angle, while usually the vomer is comparatively 

 narrow, and allows the pterygoids and palatals to articulate 

 directly with the basisphenoidal rostrum. 



" In this order the bones which enter into the formation of 

 the palate are disposed in four different modes, which may be 

 called respectively the Uromseognathous, Schizognathous, Des- 

 mognathous, and ^githognathous arrangement." The group 

 of birds characterized by these different forms of palatal arrange- 

 ment are accordingly regarded as so many Suborders. 



With respect to their palatal structure the Drom(Bognath(B 

 have a very great resemblance to the Ratitce ; but the keeled 

 sternum of the Tinamida, the family which alone constitutes 

 this Suborder, and the small angle formed by the articulation of 

 the scapula and coracoid, lead Prof. Huxley to leave them 

 among the Carinatce. 



* Following the practice of most anatomists, Prof. Huxley throughout 

 terms these bones " palatine," a word which appears to me to be formed 

 ivom. paldtium, while the adjectival derivative oipnlatnm would, I imagine, 

 b.' "piilafjil." 



