452 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 1 1 , 



In Tyrannus, in Cephalopterus, in Goracina (according to Bur- 

 meister), and perhaps in others of the American Passerines without 

 a singing-apparatus, tlie hases of the maxillo-palatines are broader 

 than their free ends, and there is no narrow stem. 



Chasmorhynchus nudicollis, however, has maxillo-palatines of the 

 ordinary character ; and in Pteroptochus megapodius they are long, 

 slender, and recurved. 



In Gymnorhina the septo-premaxillary ossification and the maxillo- 

 palatines are confluent, though the latter and the vomer remain quite 

 distinct from one another. 



In these and the majority of typical Passerine birds the palatine 

 bones are broad and comparatively flat posteriorly ; but in the 

 Finches the outer lamina of each palatine acquires a great downward 

 development, and becomes a vertical plate, the free posterior edge 

 of which is more or less notched. The anterior process of the pala- 

 tine at the same time broadens out, and becomes connected by a 

 truncated edge with the rostrum, which attains great height and 

 breadth, and is sometimes hooked anteriorly. 



The palate thus acquires a singular superficial resemblance to that 

 of a Parrot, from which it differs, however, in the separation of the 

 palatines in the middle line, in the form and size of the vomer, and' 

 in the slender, recurved, and separate maxillo-palatines (fig. 33). 



Under view of the skiill of Coc-cothrausfcs vidgar/s. The letters as before. 



Pipra erythrocephala and Tanagra cyanoptera are similar to the 

 Finches in the form of the palatines. 



The Swallows completely agree with the other Passerine birds in 

 the general form and arrangement of the bones which enter into the 

 composition of their palates. 



And the Swifts essentially resemble the Swallows, though the form 

 and proportions of the palatine bones are somewhat different (fig. 34). 



The skull of Caprimulgus, though it retains the general features 

 of the Passerine cranium, departs from the typical Passerine struc- 

 ture still further than the Swifts, the body of the palatines having 

 become exceedingly broad and flattened out, while the vomer is 



