]885.] TROCHILID^, CAPRIMULGID.E, AND CYPSELID.E. 



893 



too a strong, median, longitudinal groove traverses this part of the 

 skull. 



Whippoorwills have a far more compressed skull, in the vertical 

 direction, than the Night-hawks ; and there is a great deal about this 

 part of the skeleton in them that reminds one of the skull of some 

 of the Owls. 



Turning to the under side of the skull of ChorJediles (as shown 

 in Plate LIX. fig. 4) we find the well-developed waxillo-jjalatines 

 {Mxp) in contact with each other for their entire lengths in the 

 median line. In very old Night-hawks this close union finally 

 results in anchylosis, thus producing a perfect direct deymognathous 

 condition of type of palatal structure in these birds. The broad 



Fig. A. 



Under view of the Skull of CajyTiraulgus europaus (.X2) (after Huxley). 



Pmx, premaxillary ; Mxp, maxillo-palatine ; Vo, vomer ; PI, palatine ; 



Pt, pterygoid. 



and long vomer {Vo), with its median carination beneath, merges 

 with the palatines posteriorly, while in front its free tip just rests 

 in a notch found at the middle point of the apposed maxillo- 

 palatines behind. 



Nuttall's Whippoorwill exhibits a very different condition of these 



parts from this ; in it we find the maxillo-palatines are well 



separated from each other in the median line, and fail to come in 



contact with the vomer above them. This latter bone is even 



Pnoc. ZooL. Soc— 1885, No. LVIII. 58 



