GALL I L>!)9 



plates, ending in a curved point very much like those of some 

 passerines (e.g. Pteroptochus). Each is vacuolate posteriorly 

 in Talegalla. They do not nearly come into contact in the 

 middle line. In Megacephalon these bones are spongy plates, 

 which do nearly come into contact ; the palatines, slender in 

 both birds, are more bowed in Talegalla, and thus enclose a 

 wider interpalatine vacuity. The lacrymals of Talegalla are 

 small and ankylosed to the skull wall ; the ectethmoids are thin 

 plates. A curious difference in the skulls of these two birds 

 concerns the nasals and premaxillaries. In MegacepJialon 

 there is nothing worthy of special remark except the tumid 

 outer part of the nasals ; in Talegalla the premaxillary pro- 

 cess of the nasals approach each other in the middle line, 

 and cut the nasal process of the premaxillary into two, an 

 anterior and a posterior portion. 



In the Cracidas the maxillo-palatines are largish plates, 

 concave inferiorly and convex above, which in Crax globicera 

 actually come in contact for a short space, and fuse with 

 each other and w r ith the median septum. In Pauxi galeata 

 this fusion (perhaps owing to the great casque) is even better 

 marked. There is nearly a fusion in Aburria caruncidata ; 

 in Ortalis albivcutris, on the other hand, the maxillo- 

 palatines are well apart. 



In Ortalis and Aburria there is no ossification of the 

 nasal septum ; in Crax there is a median piece, which expands 

 below to become attached to (C. S elate ri) or fused with 

 (C. globicera) the maxillo-palatines. In Pauxi galeata the 

 nasal septum, as might be expected, is quite complete and 

 very strong. 



There are also in this group of gallinaceous birds, a series 

 of stages in the development of the zygoma and the post- 

 orbital processes. In Ortalis they are short ; in Abiu-ria 

 longer and convergent ; in Crax Sclatcri and Pauxi galeata 

 they meet distally, and enclose a triangular foramen ; finally 

 in Crax globicera they are completely fused throughout, and 

 form a stout triangular process. 



The lacrymals in this family are large, with a large 

 descending process. The ectethmoids are but slightly ossified. 



