GOAT-SUCKERS. 



389 



these minute details by which our whip-poor-will or the night-hawk may be distin- 

 guished from the more than hundred other forms in the different parts of the globe. 

 The tropics, however, have developed, even in this group, strangely ornamented 

 species, as, for instance, the object of the accompanying cut, the pennant-winged 

 night-jar (Cosmetornis vexillarius), and the nearly allied Macrodipteryx longipennis, 

 in which the shaft of the elongated primary is denuded except at the extremity, 

 which is broadly webbed for a considerable distance. These singular night-jars 

 are confined to Africa. Hardly less curious are the South American lyre-tailed 

 goat-suckers (Macropsalis li/ra and allies), with their enoi-mously elongated outer tail- 

 feathers. 



FIG. 189. Cosmetornis vexillarius, pennant-winged night-jar. 



The whole external habitus of the rollers, COBACIAD^E, reminds one forcibly of 

 certain Passerine birds, with which they were, indeed, associated by earlier ornitholo- 

 gists ; but their four-notched breastbone, with a pointed episternal apophysis, synpel- 

 mous arrangement of the plantar tendons, rudimentary basipterygoid processes, 

 desmognathous character of the maxillo-palatines, extreme attenuation of the vomer, 

 and furcation of the dorsal tract between the shoulder-blades, at once indicate their 

 position amongst the Picarise. We have already, on a previous page, indicated an 

 external character by which they may be easily distinguished from the foregoing 

 families, viz., the number of tail-feathers, which is twelve. Besides, their gaudy 

 colors prevent them from ever being confounded with any of the goat-suckers. 



