MACROCHIRES 



229 



fllUD 



observer is disinclined to allow a very iiear affinity between 

 the birds, it is undeniable that there are resemblances. 



The shull is schizognathous in the humming bird, 

 segithognathous in the swifts. But the segithognathism in 

 the latter is a little abnormal. Garrod has pointed out in 

 describing ' the osteology of Indicator that that bird, in 

 common with the Capitonidse, has a truncated vomer, in 

 which the truncation occurs behind the line joining the 

 maxiyo-palatines, while in the true 

 Passeres the truncation is in front of 

 this line. The swifts are intermediate, 

 the truncation being, as is shown in 

 the accompanying figure (fig. 104), 

 about on a level with the line joining 

 the inaxillo-palatines. It is true that 

 the lateral processes so characteristic 

 of the segithognathous skull are better 

 developed in the swifts than in the 

 swallows ; but, on the other hand, it 

 must be borne in mind that the un- 

 doubtedly segithognathous Indicator 

 is without these processes. In both 

 swifts and humming birds the skull is 

 holorhinal and without basipterygoid 

 processes. As to the vomer, 



HuxLBT described it as truncated ; 

 but Shufeldt finds it to end in an . 

 excessivdy fine point. In swifts the vomer is, as already 

 stated, truncated. But as to this difference and its value as 

 a means of separating the birds cf. the manifold vomer of 

 Limicolae. 



The humming birds have fourteen or fifteen {Trochilus 

 Alexandri) cervical vertebra. The Cypselidas have thirteen 

 or fourteen. Four ribs^ join the sternum on each side 



Fig, 304. — Skull op Micro- 

 pus melanoleucw. Undep. 

 View. (Aftek Shufeldt.) 



Ptux, premaxilla ; May>, masdllo- 

 palatlnes ; Vo, vomer ; iVa, 

 nasal ; PI, palatine ; Pt, ptery- 

 goid. 



glda, and Cypselidse,' P. Z. S. 1885, p. 886, and 1886, p. 501. See also Zbhntner, 

 ' Beitrage z. Entwioklung von Cypselus melba,' Arch. f. Naiurg. Ivi. 1890, p. 189 



(transl. in Ibis, 1890, p. 196). 



' Loc. cit. (on p. 196.) ' Fcrbeingek says five or six. 



