414 BIRDS OF PENNSYLVANIA. 



Crepus'cular. Pertaining to twilight. (Crepuscular birds are those which become 

 active after sunset. ) 



Cres'cent. A figure having the shape of a new moon. 



Crescent'ic. Shaped like the new moon. 



Crest. A more or less lengthened, erectile, or permanently erect, tuft of feathers 

 on top of the head. 



Crest' ed. Having a crest, as the Blue Jay. 



Crim'soii. Blood-red ; the color of the cruder sorts of carmine. 



Cris'sum. A term usually applied to the lower tail-coverts collectively, but prop- 

 erly belonging to the feathers situated between the lower tail-coverts and the 

 anal region. 



Cris'sal. Pertaining to the crissum. 



Crown. Pileus, top of head, especially the vertex. 



Cul'men. Ridge of maxilla or upper mandible. 



Cul'miiial. Pertaining to the culmen. 



Cu'neate. } Wedge-shaped. A cuneate tail has the middle feathers longest, the 



Cu'neiform. ) rest successively regularly shorter. 



D. 



Decid'uous. Temporary ; falling early. The dorsal plumes of the egret are decid- 

 uous. 



Decompos'ed. Separate ; standing apart. A decomposed crest has the feathers 

 standing away from each other. 



Decum'bent. Drooping or hanging downward. 



Decurved'. Gradually curved downward. Opposed to recurved. 



Degluti'tion. Act of swallowing. 



Den'tate. Toothed. 



Depress'ed. Flattened vertically ; broader than high. Opposite of compressed. 



Diagno'sis. A condensed statement of the characters which are exclusively ap- 

 plicable to a species, genus, or higher group ; a description which omits all 

 non-essential characters, 



Digitus. Digit Finger or toe. 



Disc. ) Set of radiating feathers surrounding the eye in some birds, especially the 



Disk. ) owls. 



Dis'tal. Remote ; situate at or near an extremity ; opposite to proximo. 



Diur'nal. Pertaining to the daytime. Among birds, those which are active during 

 the daytime and repose at night. ( Many diurnal birds, however, are nocturnal 

 in their migrations. 



Dor'sal. Pertaining to the back. 



Dor'sum. Back ; upper surface of trunk from neck to rump. 



Double-rounded. ) A doubly-forked tail has the middle and lateral feathers decid- 



Doubly-rounded. S edly longer than those between. 



Down. Small soft decomposed feathers, which clothe the nestlings of many birds, 

 and which also grow between and underneath the true feathers in the adults 

 of many others, especially the various kinds of water-fowl. 



Drab. A brownish gray color. 



Dusk'y. Of any indefinite dark color. 



E. 



Ear-cov'erts. The usually well-defined tract of feathers overyling the ears of most 

 birds. The ear-coverts (or auricular s, as they are usually termed in descrip- 

 tions) are bounded above by the backward extension of the supercilium, or 

 lateral portion of the crown, posteriorly by the occiput and nape, below by the 

 malar region or "cheeks," and anteriorily by the suborbital region. Same as 

 auriculars. 



