XXll INTRODUCTION. 



Asio, Brisson. — Bill decurved from the base; cere large; under mandible 

 notched. Nostrils oval, oblique. Facial disk complete. Conch of the ear 

 extremely large, with a semicircular operculum running the whole length in 

 front, and a raised margin behind ; auditory opening asymmetrical. Wings 

 long, the second quill generally the longest. Legs and toes feathered to 

 the claws. Head furnished with two tufts, more or less elongated (p. 283). 



Syrnium, 6'(Z''z]f;y. — Bill decurved from the base. Nostrils large. Facial disk 

 large and complete ; ears large and furnished in front with a large crescentic 

 operculum, broad below and tapering above. Wings short and rounded ; 

 the first quill very short, the fourth the longest. Tail long, concave beneath. 

 Legs and toes feathered. Head large, round and without tufts (p. 287). 



Nyctala, C. L. Brehm. — Bill short, decurved from the base ; cere iiidimentary ; 

 nostrils nearly circular ; under mandible notched. Ears large, asymmetrical, 

 and furnished in front with a well-developed operculum. Facial disk large 

 and nearly complete. Wings long, rounded. Tail short. Legs and toes 

 thickly feathered. Head large, the asymmetry of the aural region extending 

 to the skull (p. 289). 



Athene, F. Boie. — Bill decurved from the base ; cere short and swollen ; nostrils 

 oval ; lower mandible sinuated. Auditory conch large, the orifice small and 

 without an operculum. Facial disk not well defined. Wings large, the 

 third and fourth quills nearly equal in length. Legs long, covered with 

 short feathers ; toes above with bristles only, instead of feathers. Head 

 round, large and without tufts (p. 291). 



Nyctea, Stephens. — Bill decurved from the base ; nostrils large, oval ; cere 

 short ; upper mandible smooth, lower mandible notched. Facial disk 

 incomplete. Orifice of the ears moderate, without operculum. Wings of 

 moderate size ; the third quill the longest, second and fourth nearly equal. 

 Tail rounded and of moderate length. Legs and toes thickly covered with 

 feathers. Head large, round, not furnished with tufts of feathers (p. 293). 



SURNIA, Diimcril. — Bill decurved from the base and much hidden by feathers ; 

 nostrils small and rounded ; cere short ; upper mandible slightly undulated ; 

 lower inandible notched. Facial disk nearly obsolete. Orifice of the ears 

 small, without operculum. Wings short ; first quill equal to seventh, second 

 longer than fifth, third and fourth longest and .nearly equal. Tarsi rather 

 short and — with the toes — thickly feathered. Tail long and graduated. 

 Head flat and without tufts (p. 295). 



Scops, Savigny. — Bill much decurved from the base, cere small, under mandible 

 notched. Nostrils round. Facial disk incomplete above the eyes ; auditory 

 conch small, and without an operculum. Wings long, reaching to the end of 

 the tail ; the third quill generally the longest. Tarsi rather long, feathered 

 in front ; the toes naked. Head furnished with two tufts of feathers (p. 297). 



Bubo, Duma-il. — Bill short, strong, curved, compressed at the point. Nostrils 

 pierced in the cere, large, oval or rounded. Facial disk incomplete about 

 the eyes. Auditory opening, small, oval, without an operculum. Wings 

 rather short, concave ; the third and fourth quills generally the longest. 

 Legs and toes covered with feathers ; claws long. Head furnished with two 

 tufts of feathers (p. 299). 



