I20 SHUFELDT. [Vol. XVII. 



morphology, and among the first tasks undertaken by me was 

 the translation of this worthy contribution to avian anatomy 

 by my esteemed colleague in Christiania. This has been ren- 

 dered possible through the kind assistance of my young Nor- 

 wegian friend, Miss Alfhild Dagny Lowum, now my wife, who, 

 with great patience, made the literal part of this translation. 

 With this before me, Professor Collett's memoir was given 

 its English version in the language of science. My private 

 osteological cabinets contain the skeletons of many species 

 of owls, and the crania of these I have compared with his 

 researches as the labor of translation progressed, giving such 

 additional information as was thus obtained in footnotes, and 

 signed by my own initials. I have also seen fit to rearrange 

 his figures, redrawing some of them for text-figures, and retain- 

 ing those for lithography that especially demanded that kind 

 of reproduction. 



The present contribution, then, consists in a full and com- 

 plete English translation of Collett's memoir, supplemented 

 by footnotes of my own, and a reproduction of all the figures 

 given in the original Norwegian work. And to this I have 

 added some of the more recent opinions of recognized authori- 

 ties upon the subject, relative to the systematic position of 

 the StrigidcSy thus bringing the whole up to date and ren- 

 dering the entire memoir available to students of comparative 

 morphology everywhere ; it being, as it were, a comprehensive 

 treatise upon the value of certain structures to be found in 

 the head and cranium in owls in the classification of that 

 family, together with their relations to other groups of birds, 

 as those relations are understood at the present time. 



Professor Collett says : 



"The ten North-European species of the family StrigidcB, all 

 of which belong to the subfamily BiibonincB (the other sub- 

 family, which is represented by Strix Jlajmnea, does not occur 

 in Scandinavia), can be arrayed in six (6) groups based upon 

 the morphology of the cranium and upon the structure of the 

 external ear-openings and their dermal appendages." 



It is clear from the following table that only the first of these 

 groups, which includes Surnia ftmerea, Glaucidium passerinum, 



