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XVIII. Monograph of the Strigidse. By Dr. J. J. Kaup, Director of the Museum 

 at Darmstadt ; Corresponding Member. 



Read June 8, 1852. 



Subfamily I. SURNIIN^, Kaup. Day-Owls. 

 I. Glaucidium. II. Nyctale. III. Athene. IV. Surnia. V. leraglaux. 



Diagnosis. — They have the handsomest and roundest skull, with large brain, high 

 rounded front, small pneumacity. The greater number of this genus have a little ear- 

 orifice without operculum ; the feather-wreath round the ear is mostly not so distinct 

 as in the Night-Owls. No genus in this subfamily has feather-horns, or a dentellated 

 claw on the middle toe, as Strix. Most birds of this genus are Day- or Twilight- 

 Owls, except Nyctale, which is in this respect a true Night-Owl. 



Genus I. Glaucidium', Boie. 

 a. Glaucidium. b. ? c. Microglaux. d. ? e. Tanioptynx. 



Diagn. — The nostrils mostly in the middle of the swollen pea-shaped cera. The 

 first wing-feather shorter than the tenth wing-feather. Wings short, only reaching to 

 the upper coverts of the long and variegated tail. We find in this genus the smallest 

 of all the Owls ; their food is insects. 



Description. — The yellow bill curves rapidly from the cera. The lower jaw is on the 

 end and sides emarginated by four teeth-like points ; the short wings only reach to the 

 upper tail-coverts ; the webs of the wing-feathers are small, the first to the fourth 

 with emarginations ; the first wing-feather short and dentellated. Tarsi and toes very 

 well developed. The cross-banded or spotted tail as long as the body. The handsome 

 skull shows a thorn-shaped prominence on the front part of the eye-margin (Plate LVI. 

 fig. 1) ; and the zygoma has on its posterior part (fig. 2) a leaf-hke prominence, of 

 which all the true Striginm are destitute, and which is in other Surniinee not so well deve- 

 loped. AH the species have a white, black and rufous spotted collar, which reminds us 

 of the American Tinnunculi. Up to the present time we know only of three subgenera. 



Subgenus a. Glaucidium, Boie. 

 Diagn. — Nostrils in the middle of the pea-shaped cera; inner webs of the wing- 

 feathers broader, with emarginations more towards the end, and a spotted or unicolor 

 plumage. All the species are found in the southern parts of America. 



' Boie gives this name in the ' Isis ' to Strix nana et passerina. The latter species belongs to the genus Sur- 

 nia, with very different cera and nostrils. G. R. Gray and Bonaparte erroneously give this name to passerina. 



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