1 66 SHUFELDT. 



EXPLANATION OF PLATE XV. 



{^All the figures of the plates are by Professor Collett.) 



Fig. I. Skull of Surnia funerea ; anterior aspect, with mandible attached; 

 natural size. 



Fig. 2. Skull of Sumia funerea ; left lateral aspect, with mandible attached ; 

 natural size. 



Fig. 3. Head of Surnia funerea ; feathers removed and showing ear-opening; 

 natural size. 



Fig. 4. Skull of Glaucidium passeritium ; anterior aspect, with mandible 

 attached ; natural size. 



Fig. 5. Skull of Glaucidium passerinum ; left lateral aspect, with mandible 

 attached; natural size. 



Fig. 6. Head of Glaucidium passerinum ; feathers removed and showing ear- 

 opening; natural size. 



Fig. 7. Skull of Asio accipitrinus ; anterior aspect, with mandible attached ; 

 natural size. 



Fig. 8. Skull of Asio accipitrinus ; superior aspect, with mandible attached ; 

 natural size. 



