672 OWL 



done by Willughby, into two sections one in which all the species 

 exhibit tufts of feathers on the head, the so-called " ears " or 

 "horns," and the second in which the head is not tufted. The 

 artificial and therefore untrustworthy nature of this distinction was 

 shewn by Isidore Geoffroy-St. Hilaire (Ann. Sc. Nat. xxi. pp. 194- 

 203) in 1830 ; but he did not do much good in the arrangement of the 

 Owls which he then proposed ; and it was hardly until the publica- 

 tion, ten years later, of Nitzsch's Pterylographie that rational grounds 

 on which to base a division of the Owls were adduced. It then 

 became manifest that two very distinct types of pterylosis existed 

 in the group, and further it appeared that certain differences, 

 already partly shewn by Berthold (Beitr. Anat. pp. 166, 167), of 

 sternal structure coincided with the pterylological distinctions. By 

 degrees other significant differences were pointed out, till, as summed 

 up by Prof. Alphonse Milne-Edwards (Ois. foss. de la France, ii. pp. 

 474-492), there could no longer be any doubt that the bird known 

 in England as the Screech-Owl or Barn-Owl, 1 with its allies, formed 

 a section which should be most justifiably separated from all the 

 others of the group then known. Space is here wanting to state 

 particularly the pterylological distinctions which will be found 

 described at length in Nitzsch's classical work (Eng. trans, 

 pp. 70, 71), and even the chief osteological distinctions must be 

 only briefly mentioned. 2 These consist in the Screech-Owl section 

 wanting any manubrial process in front of the sternum, which has 

 its broad keel joined to the clavicles united as a furcula, while 

 posteriorly it presents an unbroken outline. In the other section, 

 of which the bird known in England as the Tawny or Brown Owl 

 is the type, there is a manubrial process ; the furcula, far from being 

 joined to the keel of the sternum, often consists but of two stylets 

 which do not even meet one another; and the posterior margin 

 of the sternum presents two pairs of projections, one pair on each 

 side, with corresponding fissures between them. Furthermore the 

 Owls of the same section shew another peculiarity in the bone 

 usually called the tarsus. This is a bony ring or loop bridging the 

 channel holding the common extensor tendon of the toes which, 

 as already noticed, is possessed by the OSPREY, but does not appear 

 in the Screech-Owl section any more than in the majority of birds. 

 The subsequent examination by M. Milne-Edwards (Nouv. Arch. 

 Mus. Mem. ser. 2, i. pp. 185-200, pis. 4, 5) of the skeleton of an 

 Owl known as Pliodilus (more correctly Photodilus) badius, hitherto 

 attached to the Screech-Owl section, shewed that, though in most of 

 its osteological characters it must be referred to the Tawny-Owl 



1 The Owl, however, which commonly breeds in barns in Sweden and perhaps 

 some other parts of Europe is our Tawny Owl, Strix stridula. 



2 A few more distinctive characters are shewn by Mr. Beddard in his paper 

 on the classification of this group (Ibis, 1888, pp. 335-344). 



