A4.6 Lucas on the Affinities of ChcBtura. [October 



same peculiar and characteristic shape in the six species of Swal- 

 lows at my disposal.* 



The maxillo-palatines of TrocJiiJics are apparently not pro- 

 longed, but it would be unsafe to affirm too postively that such 

 is the case before examining some large species, since, even if 

 present, they would be filamentous in character. 



I will touch but briefly on the vertebral column and ribs, as 

 both time and space are wanting for a careful analysis of the 

 characters contained therein. The following table shows the 

 number of vertebrae and ribs in Trochilus^ Chcctura^ and Cheli- 

 don^ the two Lijiiosce being added to show of how little value is 

 the mere number of vertebrae. L. ritfa is quoted from Eyton, 

 and while his term 'sacral' includes some presacrals and some 

 caudals, neither the total number of vertebras nor the proportion 

 of true dorsals and cervicals is thereby aftbcted. 



Trochilus. Chmtura. Chclidon. Limosa Limosa 



fedoa. rufa. 



Cervicals 13 14 13 15 12 



Presacrals S 7 8 11 7 



Sacrals 4 3 3 4- 15 



Caudals, including pj'gostjle. .. • 9 12 12 12 6 



Total 34 36 36 42 40 



Cervical ribs i 2 i 2 i 



True ribs 87687 



The term sacral is here applied to the true sacrals as defined by 

 Huxley and Parker. 



According to the above table, T. cohthris possesses one more 

 vertebra than does T. alexaudri^ while tlie arrangement of ribs 

 is also diflerent. At first sight the last, free rib seems to be 

 without a corresponding vertebra, but careful examination shows 

 that the last apparent presacral vertebra is really composed of two. 

 Very fortunately there was one specimen of Trochilus among 

 my material in which the vertebras could be clearly counted. 

 Very significant is the fact that the last rib of C/ic€i?era, like that 

 of Trochilus^ is imperfect, only the lower moiety with its attached 

 sternal rib being present. A similar condition is found in the 

 Loons, but not that I am aware of in any passerine bird. Cyp- 

 sehcs is the same as Chcctura and I venture the prediction that 

 careful dissection will reveal this rib in Pariyptila. 



*In Dr. Shufeldt's figures of Panyptila and Tachyclneta the maxillo-palatines are 

 imperfect. 



