42 ME. AV. P. PTCEAFT OX THE 



{Glaucidimn. 

 Meyascops. 



6". 3 „ „ Nyctala. 



b'. Hypapophyses obsolete, or 1-2 only ; lumbar vertebrte 4 ; fovea pudendalis with 



intervertebral perforations Strix. 



e. Neural spines low, not interlocking ; hypapophyses long, spine-like, extending 

 back to 2ud thoracic. 

 a'. 4 lumbar vertebrae ; canales ileo-lumbales opening near the middle of the strongly 



arched fovea Surnia. 



Canales ileo-lumbales opening near the anterior end of the crest of the pre- 



acetabular ilium Speotyto. 



b'. 3 lumbar vertebrse Scops. 



C. Sternum and Pectoral Girdle. 



Corpus sterni large, -with the hinder border always notched ; carina well developed, extending backwards 

 to the extreme end of the sternum ; anterior lateral processes small ; antero-lateral border of sternum 

 marked by a deep scar for the stemo-coracoideus, which extends backwards to the level of the last sternal 

 rib ; coracoid grooves but slightly overlapping ; coracoid with a large processus procoracoideus ; 

 furcula U-shaped, and lacking a hypocleideum. 



A. Sternal plate with a single pair of notches posteriorly ; furcula non-pneumatic, 



articulating with antero-ventral angle of carina by a broad facet ; distal end not 

 articulating with acrocoracoid by a special facet Strigid^. 



B. Sternal plate with a pair of notches posteriorly ; furcula pneumatic, not articulating 



with the antero-ventral angle of the carina by a facet; distal end articulating 



with the acrocoracoid by a special facet Asionid.e. 



a. Outer pair of notches relatively small, but exceeding the depth of the keel . . Asio. 



b. Outer pair of notches obsolete Huhua. 



c. Length of coracoid equals length of sternum from its anterior border to the 



base of the inner notch. 



iBubo. 

 Ketupa. 

 Surnia. 

 b' . Coracoid with a small processus lateralis basalis Speotyto. 



i Scops. 

 Ninox. 



a. ijengxn oi coracoiu equais lengtu ui carina < 



'i Athene. 



Glaucidium. 



Syrnium. 



e. Spina externa of sternum wanting. 



a. Ventral lip of coracoid groove entire Nyctala. 



y. Site of spina externa marked by notch Gyiimasio. 



