188 STRUCTURE AND CLASSIFICATION OF BIRDS 



quently Y-shaped form of the pterygoids. An outer 

 forwardly directed process is given off near to their articula- 

 tion with the quadrate. The extraordinary hyoid connected 

 with the long and exsertile tongue is, of course, a marked 

 feature of the group. The long distal piece of the bran- 

 chials curves over and furrows the cranium of those species 

 in which it exists. 



In the wryneck (Jynx) the vomers are small, but 

 thoroughly ' picine.' The pterygoids have, however, no 

 forwardly directed process, and do not extend quite so far 

 over the palatines. 



There are fourteen cervical vertebrce. Hsemapophyses 

 do not extend behind the first dorsal. There is a complete 

 canal for the carotids formed in the cervical region by the 

 hsemapopSyses. Four vertebrae enter into the formation of 

 this in Thriponax Feddeni? The sternum has two notches on 

 either side, and has the spina exterior only, which is bifid. 

 Four ribs reach it. The clavicles form a U-shaped furcula, 

 but are expanded above, as in the toucans and barbets. 



The Bucconidse is a South American family of zygodac- 

 tyle birds whose anatomy ^ is at present but little known, and 

 whose affinities are therefore doubtful. It is only provi- 

 sionally that I place them in the present position. 



Bucco maculatus has a nude oil gland and twelve rectrices. 

 The inferior /ea^Aer tract starts from the symphysis, leaving 

 a bare space on either side ; it divides at the angle of the 

 jaw, and thence the two halves remain separate. Each of 

 them gives off a stout outer pectoral branch. The dorsal 

 tract is in two quite separate parts, separated by a good 

 space ; the' posterior part is forked for half its length, 

 tapering anteriorly to a point. 



In Monasa panamensis each part of the posterior fork 



' This character is nearly unique among anomalogonatous birds. I 

 describe it, however, above (p. 176) in Gymnorhina. The nearest possible ally 

 in which it occurs is a parrot. 



^ GiEBEL, ' Zur Osteologie der Gattung Monasa,' Zeitschr. f. d. ges. Naturw. 

 xviii. 1861, p. 121. 



