1907.] TO THE OSTEOLOGY OF BIRDS. 365 



the opposite side forms a long tubvilar cavity, open below, and 

 I'oofed above for the most part by the vomer. 



In my eai^lier papers on the Eurylsemidse and Tracheophone 

 Passeres (5) I have described the upper lamina of this scroll as 

 afFording a surface to facilitate gliding along the parasphenoidal 

 rostrum. As a matter of fact, this is not really the case : the 

 palatine hardly touches the rostrum, which is embraced only by 

 the distally expanded ends of the pterygoid. 



The free end of the palatine rod — caudad of the bar which 

 connects this with the body of the bone — is conspicuously long 

 and spike-like in many Tyrannidse, the Vangidae, and Artamidaj 

 (if these two can be regarded as distinct families) and Gymnorhina?. 

 This spur is referred by W. K. Parker to the " transpalatine," but 

 it is doubtful whether this homology exists. 



The quadrate presents no very striking characteristics. It 

 differs from that of the Eurylsemidfe and the Tracheophone 

 Passeres in that, except in the Phytotomidae, the quadrato-jugal 

 bar is not set out from the quadrate by a cylindrical boss of bone 

 laterad of the outer articular condyle. The condyle, however, 

 stands far out, laterad,, of the long axis of the quadrate. The 

 internal mandibular condyle of the quadrate is, in the Phyto- 

 tomidae, conspicuous for its large size and spherical shape. The 

 squamosal and otic heads are well marked ; and the orbital process 

 is conspicuous for its great length, terminating in a point, except 

 in the Phytotomidte wherein the orbital process is greatly reduced. 



The Mandible. 



The mandible, like the quadrate, affords no very important 

 features. The lateral vacuity, which is placed far back, is always 

 small. The angular process is always short, especially in the 

 Gymnorhinse and Vangid^e, and in Pitangus among the Tyrannida^. 

 In Artamus and Gymnorhina the mandible is truncated posteriorly. 

 The internal angular process is of moderate length, though in 

 Pityriasis and Artaniia it must be described as very short. 



The Ryoid. 



Unfortunately in only three skeletons of the whole series 

 examined during the preparation of this paper are the hyoid bones 

 preserved. At the time when these skeletons were made no 

 great care was taken to preserve these bones. As these hyoids 

 belong to very different forms and have not hitherto apparently 

 been recorded, we may briefly indicate their structure. 



The Dicruridge are represented in this matter by Edolius 

 forficatus. Herein basi-hyals are represented by a pair of rod- 

 shaped bones lying side by side, and terminating, posteiiorly, in a 

 free spine. Basi-branchials 1-2 are fused, and both agree in 

 being much elongated. The cerato-branchials are of moderate 

 length ; the epi-branchials are unfortunately missing. 



In JSfewtonia the basi-hyals are relatively longer, narrower, and 

 enclose a space between them. Basi-branchial 1 is shorter than 2, 



Proc. Zool. Soc— 1907, l^o. XXY. 25 



