142 GENERAL ORNITHOLOGY part n 



grouse family. The ruffed grouse ^ has a singular umbrella-like 

 tuft on each side of the neck : the pinnated grouse ^ has still more 

 curious winglets in the same situation, covering bare distensible 

 skin: the sharp -tailed grouse^ is in somewhat similar but less 

 pronounced case ; while the cock-of-the-plains * has some extra- 

 ordinary jugular developments of feathers in connection with his 

 subcutaneous tympanum. Cervix proper almost never has modified 

 feathers, but often a transverse coloration different from that of the 

 rest of the upper parts ; when conspicuous, this is called " cervical 

 collar," to distinguish it from the guttural or jugular " collars " or 

 rings of colour. Nucha is frequently similarly marked with a 

 " nuchal band " ; often special developments there take the form of 

 lengthening of the feathers, and we have a "nuchal crest." More 

 particularly in birds of largely variegated colours, guttur and 

 jugulum are marked lengthwise with stripes and streaks, of which 

 those on the sides are apt to be different from those along the 

 middle line in front. Jugulum occasionally has lengthened feathers, 

 as in many herons. Higher up, the neck in front may have 

 variously lengthened or otherwise modified feathers. Conspicuous 

 among these are the ruffs, or tippets, of some birds, especially of the 

 grebe family (Podicipedidce), and, above all other English birds, of 

 the male ruff (Machetes pugnax). But these, and a few other modi- 

 fications of the feathers of the upper neck, are more conveniently 

 considered with those of the 



Head. — Though smaller than any of the areas already con- 

 sidered, the head has been more minutely mapped out, and much 

 detail is required by the number and importance of its recognisable 

 parts or regions. Without intending to mention all that have 

 been named, I describe all needed to be known for any practical 

 purposes. 



" Top of the head " is a collective term for all the upper surface, 

 from base of bill to nape, and laterally to about the level of the 

 upper border of the eyes ; this is the pileum or " cap " (Fig. 25, 1, 4, 

 6) ; it is divided into three portions. The fwehead, or frontal 

 region, or simply "the front" (Lat. frons ; Fig. 25, 1), includes all 

 that slopes upward from the bill, — generally to about opposite the 

 anterior border of the eyes. Middle head or crown (Lat. cffrona) or 

 vertex (Lat. Kg. 25, 1) includes the top of the head proper, or 

 highest part, from the rise of the forehead to the fall of the hind- 

 head towards nucha. This slope is the hind-head, or occiput (Lat. 

 Fig. 25, 6). The lateral border of all three constitutes the super- 

 ciliary line, that is, the line over the eye (Lat. mipe:i; over ; cilia, 



^ Bonasa umhellus, which closely resembles the European hazel - grouse, B. 

 ietulina. '^ Cupidonia cupido. 



^ Pedicecetes phasianellus. * Centrocercus urophasiantis. 



