EXTERNAL PARTS OF BIRDS.- TOPOGRAPHY. 



95 



between them is called the interscapulare (fig. 25, 10) ; it is often marked, as in the chipping 

 sparrow, with streaks or some (jther distinctive coloration. A part of dorsum, lying between 

 interscapulare and uropygium, is sometimes recognized as the "lower back" (Lat. tergmn); but 

 this distinction is not practically useful. To uropygium probably also belong the feathers of 

 the pteryl(E femorales, or at any rate these are commonly included with the rump in descrip- 

 tions; but they more properly represent the flmiks (Lat. ilia, or hypochondria); that is, sides 

 of the rump. They are sometimes the seat of largely developed or otherwise peculiarly 

 modified feathers, as the snowy tiank plumes of the M'hite -bellied swift (Pamjptila saxatilis) or 

 violet-green swallow (Tachi/cineta thalassina), which meet over the rump. The whole of 

 notseum, taken together with the upper surfaces of the wdngs, is called the mantle (Lat. stragii- 

 lum, a cloak) ; often a convenient term, as in describing gulls and terns for example. In like 

 manner, the 



Fig. 25. — Topography of a Bird. 1, forehead (frons). 2, lore. 3, clrcumocular region. 4, crown {vertex). 

 5, eye. 6, hlndhead (oce/pitri. 7, nape (?iMc;ta). 8, hind neck (cerrta;). 9, side of neck. 10, interscapular region. 

 11, dorsum, or back proper, including 10. 12, notmum, or upper part of body proper, including 10, 11, and 13. 

 Vi,Tami,(wropy()ium). 14, upper tail-coverts. 15, tail. 16, under tail-coverts (cWsswrn). 17, tarsus. 18, abdo- 

 men. 19, hind toe (^^iwa;). 20, jras^rcEMTW, including 18 and 24. 21, outer or fourth toe. 22, middle or third toe. 

 23, side of the body. 24, breast (^ec<Ms). 25, primaries. 26, secondaries. 27, tertiaries; nos. 25, 26, 27 are all 

 remiges. 28, primary coverts. 29, ahda, or bastard wing. 30, greater coverts. 31, median coverts. 32, lesser 

 coverts. 33, the "throat," including 34, 37, 38. Zi, .nigulum or lower throat. 35, auricnlars. 36, malar region. 

 37, ^M to, or middle throat. 38, mentum, or chin. 39, angle of commissure, or corner of mouth. 40, ramus of 

 under mandible. 41, side of under mandible. 42, gonys. 43, apex, or tip of bill. 44, toiyiia, or cutting edges of 

 the bill. 45, ciUmen, or ridge of upper mandible, corresponding to gonys. 46, side of upper mandible. 47, nostril. 

 48 passes across the bill a little in front of its base. 



Gastraeum is subdivided into regions, called, in general terms, breast (Lat. pectus ; fig. 25, 

 21), belli/ (Lat. abdomen ; fig. 25, 18), and sides of the body (Lat. pleura ; fig. 25, 23). The 

 " sides" or pleurae belong really as much to the dorsal as to the ventral aspects of a bird's 

 body ; but in consequence of the underneath -fi-eighted shape, the line we drew passes so high 

 up along them, that they are almost entirely given over to gastrseum. The breast beginsov*" 



