174 



GENEBAL OBNITHOLOGY. 



whole hyoid apparatus of the woodpeckers is specially modified ; the basihyal is very long 

 and slender, bearing stunted cerato- and glosso-hyals at its extreme end ; there is no uro- 

 hyal, or only a rudiment ; the cerato-branchials are long, and the epibranchials so extraordi- 

 narily elongated in some species as to curl up over the back of the skull and forward along the 

 top of the skull to a variable distance ; sometimes, as in fig. 73, curling around the orbit of the 

 eye, or, as in fig. 74, running into the nostril to the tip of the beak. In such cases they 

 bundle together in passing forward over the skull, and go obliquely to one side. (Derivation 

 of the terms in this paragraph : hyal is another form of hyoid; branchial, Lat. branchia, 

 gills ; basi-, Lat. basis, base ; cerato-, Gr. Ktpas, Kfparos, keras, keratos, horn ; epi-, Gr. eVt, 

 epi, upon; stylo-, Lat. stylus, a pen; glosso-, Gr. yXaxraa, glossa, tongue; uro-, Gr. ovpa, 

 oura, tail ; thyro-, Gr. 6vpt6s, thureos, a shield.) 



Figs. 73, 74. —Under fig. side view of a woodpecker's (Picus) 

 skull, showing the long slender basihyal {hh), bearing slight elements 

 at its fore end, no uroyhal, and extraordinarily long thyrohyals 

 (chr, ebr) curving up over back of skull and curling together around 

 orbit of the right eye. Upper flg. top view of skull of Colaptes, 

 showing thyroliyals running along the skull and into right nostril 

 to end of the bill. (Dr. R. W. Shufeldt, U. S. A.) 



Other Bones of the Skull. ^ 



The articulation of the lower jaw 

 with the quadrate may have certain 

 sesamoids. Thus, there are two 

 such sclerosteous or ligament-bones 

 in the external lateral ligament of 

 the raven's jaw-joint, and the long 

 occipital style of the cormorant and 

 snake-bird is of the same character,, 

 being an ossification in the nuchal 

 ligament of the neck. The siphon- 

 like tube which conveys air from 

 the outer ear-passage to the hollow 

 of the mandible may ossify, as it 

 does in an old raven, resulting in 

 a neat tubular ''air-bone" or at- 

 viosteon (Gr. arpos, air). 



Types of Palatal Structure 



The arrangement of the bones of the- 

 palate in birds results in several 

 types of structure, first defined by 

 Huxley and applied to the classification of birds. These are the dromccognathous, schizog- 

 nathous, desmognathous and eegithognathous ; to which Parker has added the saurognathous. 

 Huxley proposed to make the primary division of Carinate birds upon this score ; and since 

 the plan could not be made to work in his hands, it is certainly futile for any one else to 

 demonstrate again the impossibility of establishing the higher groups of birds upon any one 

 set of characters, — upon the modifications of any one structure. Nevertheless, when duly 

 co-ordinated with other characters, palatal structure becomes of the utmost importance in 

 defining large groups of birds. It is necessary, therefore, for the student to clearly understand 

 this matter, which I will lay before him as nearly as ])ossible in the words of the authors 

 just mentioned. 



Dromaeognathism (Gr. hpopaioi, dromaios, a runner: genus-name of the emeu). — All the 

 Ratite birds, and the tinamous alone of Carinate birds, are dromccognathous. "The posterior- 

 ends of the palatines and the anterior ends of the pterygoids are A'ery imperfectly, or ntjt at all, 

 articulated with the basisphenoidal rostrum, being usually separated from it, and supported by 

 the broad, cleft, hinder end of the vomer. Strong basipterygoid processes, arising from the- 



