284 



STRUCTURE AND CLASSIFICATION OF BIRDS 



formula of the leg, as stated in the definition, is ABX Y + . 

 Both peroneals are present. The deep flexor tendons are 

 bound by a vinculum, which is single in Corytlmix and 

 double in Schizorhis. 



The skull of Conjthaix is barely desmogiiathous, and 

 by no manner of means especially like that of a cuckoo, 

 to which group the Musophagi have been often compared. 

 The hinge in the middle of the face is nearly complete, but 

 there is a bridge on each side, formed b t y an ankylosis 

 between the frontal and nasal. The holorhinal nostrils are 

 situated very far forwards, and each has, as PAEKEE ' has 

 pointed out, an osseous fold upon the ossified internarial 

 septum. The maxillo-palatines diverge from each other 

 posteriorly for a much longer space than in any cuckoo. 

 The ascending laminae of the palatines come into contact 

 for a very brief space over the rostrum in front, and are 

 continued forward for a short distance as a sharp spike. 

 Between them lies a minute interpalatine splint (or vomer). 

 The interorbital septum is moderately fenestrate. The 

 lacrymal bones are of some size, and the descending process 

 is closely applied to, but does not fuse with, the square 

 ectethmoid process ; connected with both is a small os 

 uncinatum, which reaches the palatine. 2 



Bony nostrils . 

 Ectetlimoid 



Palatinrx 



Maxillo-palati ncs 

 Jugal bar 



Cuculi 



dorsal Not so continuous. 



Close to fronto-nasal Near end of bill. 



hinge. 

 Continuous with 



wall of orbit. 

 Ascending laminae come 



into contact posti'riurlij 



for a considerable 



Ascending laminae come 

 into contact anteriorly 

 for a sliort space. 



space. 



Move completely fused. 

 Expanded where it joins 



maxilla on, or close to, 



ventral surface. 



Less completely fused. 



Not expanded ; junction 

 with face higher up, 

 very much as in 

 parrots. 



In view of the general opinion as to the nearness of the 



1 In his paper upon Opixtliocnunis. See below, p. 286, footnote 7 . 



2 J. T. REINHARDT, Yid. Medd. Kjobenhavn, 1871, p. 3'2(>. 



