200 STRIGIDiE, OMXS. 



mounted on long legs, like a crane, and has several other more important structural 

 modifications. The other three families occur in this country ; and the following 

 accounts are sulliciently explicit to illustrate the order, without further remark 

 in this connection. 



Family STRIGIDiE. Owls. 



Head ver}' large, and especially broad from side to side, but shortened length- 

 wise, the "face" thus formed further defined by a more or less complete "ruff," or 

 circlet of radiating feathers of peculiar texture, on each side. Ej'es very large, 

 looking more or less directly forward, set in a circlet of radiating bristly feathers, 

 and overarched l)y a superciliary shield. External ears extreniel}^ large, often pro- 

 vided with an operculum or movable flap, presenting the nearest approach, among 

 birds, to the ear-conch of mammals. Bill shaped much as in other ordinary rapa- 

 cious birds, but thickly beset at base with close-pressed antrorse bristly feathers. 

 Nostrils large, commoulj^ opening at the edge of the cere rather than entirely in its 

 substance. Hallux of average length, not obviously elevated in any case ; outer 

 toe more or less perfectly versatile (bat never permanentlj^ reversed), and shorter 

 than the inner toe. Claws all verj^ long, much curved and extremelj' sharp, that of 

 the middle toe pectinate in some species. As a rule, the tarsi are more or less 

 completel}^ feathered, and the whole foot is often thus covered. Among numerous 

 osteological characters majr be mentioned the wide separation of the inner and 

 outer tablets of the brain case by intervention of light spongy diploe ; the 

 commonly 4-notched sternum, and a peculiar structure of the tarso-metatarsus. 

 The gullet is capacious but not dilated into a special crop ; the gizzard is only 

 moderately muscular ; the intestines are short and wide ; the coeca are extremely 

 long and club-shaped. The syrinx has one pair of intrinsic muscles. The feathers 

 have no aftershaft, and the general plumage is very soft and blended. 



The Nocturnal Birds of Prejr will be immediately recognized bjr their peculiar 

 phj'siognom3', independentlj' of the technical characters that mark them as a natural, 

 sharply defined family. They are a highlj' monomorphic group, without extremes 

 of aberrant form ; but the ease with which they are collectively defined is a measure 

 of the diiliculty of their rigid subdivision, and the subfamilies are not yet satis- 

 factorily determined. Too much stress appears to have been laid upon the trivial, 

 although evident, circumstance of presence or absence of the peculiar ear-tufts that 

 many species possess : more reliable characters may probably be drawn from the 

 structure of the external ear, and facial disk, the modifications of which appear 

 to bear directly upon mode of life, these parts being as a rule most highlj^ de^'eloped 

 in the more nocturnal species ; while some points of internal structure maj' yet be 

 found correspondent. One group, of which the barn owl, Strix Jlammo.a, is the 

 tj^pe, seems very distinct in the angular contour and high development of the facial 

 disk, pectination of the middle claw, and otliar characters ; and probably the rest 

 of the family fall in two other groups ; but I do not deem it expedient to present 

 subfamilies on this occasion. 



As is well known, owls are eminently nocturnal birds ; but to this rule there are 

 numerous striking exceptions. This general habit is correspondent to the modifi- 

 cation of the eyes, the size and structure of which enable the birds to see by night, 

 and cause them to sufl'cr from the glare of the suulight. Most species pass the 

 daytime secreted in hollow trees, or dense foliage and other dusky retreats, resuming 

 their wonted activity after nightfall. Owing to the peculiar texture of the plumage 



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