OSTEOLOGY 



137 



c — 



and in the hawks bearing a second and separate bone 

 behind. These bones appear sometimes to have a definite 

 relation to the cartilaginous ectethmoids. I do not refer so 

 much to the fact that they sometimes entirely fuse with 

 them (and with the skull wall) as to the varying size and 

 relations of the two. In the kingfishers, for example, where 

 the ectethmoids are small, the lacrymals are large, and have 

 below an expanded plate which supplies the place of the 

 feeble ectethmoid. When the lacrymal does not reach the 

 orbital margin, as in Gorvus, the 

 ectethmoid does, and, as it were, takes 

 its place. In many birds belonging 

 to quite different orders there is a 

 small bone connecting the lower end 

 of the lacrymal, or of the ectethmoid, 

 with either the palatine or the jugal 

 bar ; this bone has been termed ' os 

 crochu,' OS uncinatum, os lacrymo- 

 palatinum, and will be described in 

 detail in those birds where it is to 

 be found.' It may be that the os 

 uncinatum should have been de- 

 scribed as one of cartilaginous bones 

 of the cranium. In some birds (tina- Fig. 76.— Hyoid op Latha- 

 mous, Menura, Psophia, and Arhori- Z^a^t)!^'''"^ ^^''™'' 



cola) there is a set of supraorbital 6, basmyal ; », hypobranohlal ; *, 

 -I . . ,-, T . . -, ceratobrauchial ; «, urohyal ; e, 



bones margining the orbits above. entoglossum;^, parahyal;c,oon- 



The base of the brain case is protected 



by a large basitemporal, which has sometimes (e.g. Apteryx) 

 a long rostrum in front. The maxillae are sometimes sepa- 

 rate from each other, and at times united across the middle 

 line by more or less extensive ossifications, of which a pro- 

 minent one, and with the appearance of a separate bOne, 

 is the maxillo-palatine. The premaxillaries in front of these 

 send back a long process extending as far as the nasals. , 

 2. To this category, perhaps, belong the squa,mosal, 



' ' See under Cariama, Tubinares, Steganopodes, Musopbagi, where cross, 

 references will be found. 



