398 CORACIIFORiMES chap. 



them in close proximity to tlie Nightjar alliance {Ca'primulgi), 

 the members of which they certainly resemble in their soft 

 plumage, large eyes, and crepuscular tendencies. 



Fam. VII. Strigidae. — This, which contains all the Owls, may 

 be divided into two Sub-families, (1) Stnrjinae and (2) Bitboninae} 

 In the former, or Screech-Owl section,^ the sternum has its broad 

 keel joined to the furcula, and exhibits no notches behind ; in 

 the latter, containing the remaining genera, the clavicles do not 

 always form a furcula, nor do they meet the sternum, which 

 shews one or two pairs of projections posteriorly. In this section, 

 moreover, there is a bony loop bridging the channel in the meta- 

 tarsus which contains the common extensor tendon of the toes, 

 as is the case in the Osprey. Pterylography would lead to the 

 same subdivisions. Between the two groups lie PhotocUlus of 

 the Indian Eegion, now referred to the Buboninae, and Heliodilus 

 of Madagascar, which is classed with the Striginae. 



The head is large ; the neck short and thin ; the bill moderate 

 in length, but stout, with a sharp hook at the tip ; the culmen is 

 usually curved, but is straighter in Strix, while the basal cere is 

 more or less covered by feathering, especially in NycUa. The short, 

 strong metatarsi — somewhat longer in Speotyto and Sceloglaux — 

 are flattened in front and covered with small scales. They are 

 usually feathered, though in Ketwpa and Scotopelia they are all 

 but bare, while they are partly so in Scops gymnopus and S. nudipes, 

 the two former having the toes provided with spicules below, as 

 in Pandion. Many forms have the plumage extended as a thick 

 covering of soft feathers or bristles to the claws, which are normally 

 long, sharp, and curved, that of the middle toe having a serrated 

 margin in the Striginae. The digits are padded beneath, and the 

 fourth of them is reversible at will, enabling Owls to perch with 

 either one or two toes behind. The wings are long, or fairly so, 

 very broad, and more or less rounded. Scops and Strix being in- 

 stances of greater length, Buho, Sceloglaux, Speotyto, and Photo- 

 dilus of shortness ; the primaries number eleven and the secondaries 

 from eleven to eighteen. ' The tail of ten or twelve rectrices is usually 

 short and somewhat rounded, though longer in Surnia. The laroe 



1 Cf. Milue-Edwards, Oiseaux fossiles de la Prance, ii. 1871, pp. 474-192 ; and 

 Tor further details A. Newton, Did. Birds, 1894, pp. 671-674. 



2 Brisson, who divided the genus Strix, made the Tawny Owl its type ; if this 

 be accepted, Striginae must become Alucinae and Buboninae become Striginae. 



