MORPHOLOGY OF THE OWLS. 229 



external aperture of the ear, lies a single longitudinal row of some 6-7 feathers distinctly 

 longer than those in the neighbourhood, whose shafts are directed outwards and back- 

 Avards; they form the " ear "-tufts or " horns." Running along the outside of the bases 

 of these '• ear "-tufts is an oblong apterium. 



Occipital are a. — This is a backward continuation of the parietal area, terminating 

 at the occiput. Tlie feathers radiate from the middle line outwards and somewhat 

 upwards. As they approach the free edges of the post-aural ibid they gradually decrease 

 in size, and become at the same time more thickly planted. 



Loreal area (PI. 25. fig. 2). — This is occujned by a somewliat cresceutie and 

 densely-packed group of stiff-shafted feathers (p. 25G). Its upper limb runs backwards 

 to terminate in the region above the middle of the eye. The lower limb runs downwards 

 and backwards behind the gape to join the feathers of the operculum. 



Ocular are a. — In consequence of the fact that the eyes, instead of being sunk 

 entirely within the orbit, are directed outwards and forwards, a considerable portion of 

 the sclerotic ring is brought into close relation with the outer world. This portion is 

 protected by the eyelid, which is on this account of greater relative size than in other 

 birds. It is clothed by a more or less regular series of semicircular rows of feathers, 

 decreasing in size as they approach its free edge. 



Circum aural area. — As its name implies, this area concerns the region around 

 the external aperture of the ear. In the present species, and in some o^her Owls, this 

 region is characterized by the considerable development of membranous folds of skin — 

 the pre- and postaural folds. When the former is largely developed, it is known as the 

 " operculum." 



Operculum. — The feathers seated along tlie free edge of the operculum (PL 25. 

 fig. 2) are aU elongated, with narrow vanes ; they form a series of from 3 to 4 rows 

 liaving an outward and upward direction. Hunning parallel with the feathers on the 

 free edge, but separated by a considerable apterium, is a single row of feathers, differing 

 only from those of the free edge in that they are of a more slender character. 



Postaural fold. — The feathers seated along the free edge of this fold form the 

 periphery of the disc (PI. 25. fig. 2). They belong respectively to the fronto-parietal, 

 occipital, and ramal areas, and are continvied downwards and forwards to unite in the 

 middle line near the syrapliysis of the mandil^le. They are compai-atively short, slender, 

 and nai'row-vaned, so densely packed that their embedded bases form a thickened rim to 

 the fold. The feathers occupying the lower segment of this " rim " are directed upwards, 

 and those in the lower segment downwards ; as a consequence, where the two series meet a 

 notch is formed (PI. 27. fig. 3). This point was apparently first noticed by Kaup (p. 225). 



Ramal area (PL 25. fig. 2). — This may be divided into two sections — an anterior, 

 extending from the gape on each side of the ramus to the junction of the pre- and post 

 aural folds, and a posterior strongly-marked triangular section, the base of which merges 

 with the feathers of the postaural fold. 



Inter ramal are a. — The space from the symphysis of the mandible Ijackwards to 

 the point where the inferior limb of the crescentic peripheral disc-feathers converges is 

 occupied by a broad truncated-conical patch of elongated, slender, forwardly-directed 



