414 
BIRDS OF PENNSYLVANIA . 
Crepuscular.—Pertaining to twilight. (Crepuscular birds are those w r hich 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'son.—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'minal.—Pertaining to the culmen. 
Cu'neate. \ Wedge-shaped. A cuneate tail has the middle feathers longest, the 
Cu'neiform. S rest successively regularly shorter. 
D. 
Deciduous.—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. 
Deglutition.—Act of swallowing. 
Den tate.—Toothed. 
Depressed.—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 proximat. 
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 oveiyling the ears of most 
birds. The ear-coverts (or auriculars , 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. 
