An egg of this Owl, taken from the oviduct of its parent by Mr. B. R. Ross, April 16, at Fort Simpson, measures 1.50 inches in length by 1.20 in breadth. It is of oval shape, and of a dull-white color. Another egg measures 1.62 by 1.30 inches, is of a rounded oval, equally obtuse at either end, and of a yellowish-white color. It was taken by Mr. MacFarlane at Fort Anderson. _Genus_ GLAUCIDIUM, BOIE. _Glaucidium_, BOIE, Isis, 1826, 970. _Microptynx_, KAUP. (Type, _Strix passerina_, LINN.) _Microglaux_, KAUP. (Type, _Strix havanense_, KAUP, = _G. siju_ (D’ORB.) CAB.) ? _Taenioptynx_, KAUP. (Type, _Noctua brodiei_, BURT.) GEN. CHAR. Size very small; head rather small; bill and feet very strong and robust; no ear-tufts; tail long, about three fourths as long as the wing, rounded. Nostrils circular, opening in the middle of the inflated cere-membrane (except in _G. siju_). Tarsus about equal to the middle toe, densely feathered; toes haired. Four outer quills with their inner webs emarginated; third to fourth longest. Ear-conch very small, simple, rounded. Bill yellowish (except in _G. phalænoides_?); iris yellow. The genus is most largely developed within the tropical regions, only one species (_G. passerinum_) belonging to the cold temperate zone, and this is found on both continents. They are the most robustly organized of all Owls, and, for their size, are very predatory, as in the next genus (_Micrathene_), though themselves hardly larger than a Sparrow, they frequently feed upon small birds, and, no doubt, often destroy the passerine species of nearly their own size. Like the most of the group to which this genus belongs, they are diurnal in their habits, and fly about during the brightest sunshine. They inhabit chiefly dense forests, and for this reason, are less well known than the more easily accessible Owls. [Illustration: =36874= _Glaucidium californicum._] The following synopsis includes only the North American and Mexican species of _Glaucidium_. In tropical America are several others very distinct from those here given. Species and Races. COMMON CHARACTERS. Above brown, varying from nearly gray to bright ferruginous, in some species this color interrupted by a more or less distinct whitish nuchal collar, with an adjacent blackish spot (sometimes concealed) on each side of the neck. Tail with narrow bands. Beneath white, the sides striped with brown or blackish. Throat and jugulum white, with a dusky collar between. Crown speckled or streaked with lighter; wings more or less spotted with the same. =A.= Markings on the crown circular, or dot-like. 1. =G. passerinum.= Tail with six to eight narrow white bands. Upper parts varying from brownish-gray to chocolate-brown. Ground-color of the lower parts pure white. Tail, and stripes on sides, not darker than the back; tail-bands six, and continuous; toes rather thickly feathered. _Hab._ Europe …