210 STRUCTURE AND CLASSLFIUATEON OF BIRDS 



as in the kingfishers. The skull is desmognathous, holorhinal, 

 without basipterygoid processes. The descending Hmb of 

 the lacrymal nearly unites — is connected by cartilage — with 

 the slender ectethmoid, thus forming a ring. The nostrils 

 in the dried skull are pervious. 



The desmognathism of Merops is different from that of its 

 allies. The maxillo-palatines are long, slender, recurved 

 plates, like those of passerines. They are fused in the middle 

 line to a broad plate of bone, but the free ends of the maxillo- 

 palatines extend backwards for some distance independently 

 of this. The palate in front of the maxillo-palatines is to 

 some extent vacuolate. The vomer is a single rodlike bone. 



The Momotidae ' are South and Central American, com- 

 prising the genera (perhaps subgenera) Momotus, Hylomanes, 

 Baryphthengus, and some others. They are placed by 

 Gadow in close association with the todies, but there are 

 various points in which they differ from that family, upon 

 which stress has been laid by Forbes. It is mainly to the 

 last-mentioned observer ^ and to GtAEEOD ^ that the existing 

 knowledge of the family is due. The external characters of 

 the family show some variation ; in Momotus the oil gland 

 is quite nude ; in Hylomanes and Eumomota the apex is 

 furnished with a few small plumes. Momotus has twelve 

 rectrices ; Hylomanes, Prionorhynchus, Baryphthengus, ten. 

 A remarkable characteristic of the motmots are the two 

 central racket-shaped rectrices, which matter was investi- 

 gated twenty years ago by Salvin.'' It appears that 

 the original account given by Wateeton of the birds nibbling 

 off the vanes is perfectly correct, for it was observed by 

 Baetlbtt at the Zoological Society's Gardens. As a rule 

 the bird only nibbles at the two long central rectrices, but 

 Salvin reports a case where a bird had sought fresh fields 

 and had attacked others of its feathers. It is a very remark- 



' J. MuBiE, ' On the Motmots and their Affinities,' Ibis (3), ii. 1872, p. 383. 

 ■' Collected papers, passim. 



' Collected papers, passim, ' On the Systematic Position of Momotida;,' 

 P Z. S. 1878, p. 100. 



' ' On the Tail Feathers of Momotus,' P. Z. S. 1873, p. 429. 



