256 ME. W. P. PTCRAFT ON THE 



FterylfB : — 



Pt. cajyft/s. — The papillne which will give rise to the peripheral disc-feathers are fairly 

 sharply defined from the rest of those covering the head, as a narrow baud of closely-set 

 raised points. The aperture of the ear is nearly circular ; its vertical axis is less than 

 that of the longitudinal axis of the closed eyelid. There is no trace of an operculum. 



Ft. spinalis. — Interscapular fork with the branches very long, and joining those of 

 the lumbar fork so as to enclose a space. At the junction of the free ends of the lumbar 

 fork with those of the interscapular fork, a side branch is given off from each to the 

 posterior end of the Pt. humeralis. 



Stages IV. and V. agree, so far as the distribution of the feathers is concerned, with 

 Stage III. In Stage V. the first trace of the operculum appears. 



VI. Structure op the Feathers. 



Contour-feathers. — These, in the Ow^ls, are of considerable length, and soft and some- 

 what loose in texture. There is no aftershaft. The remiges in many, e. g. Asio, Bubo, 

 present on the upper surface of the vexillum a very characteristic velvety pile, due to 

 the enormous elongation of the free ends of the distal radii, which extend forw^ards over 

 as many as three rami, not including the ramus from which they arise. 



The feathers composing the facial disc present a few points w^orthy of notice. Round 

 the free edge of the operculum they have an elongated and rigid shaft, bearing 

 numerous moderately long rami, which form a discontinuous vexillum. The most distal 

 rami break up into about three short branches, all of which bear fila, thus giving the tips 

 ■ — under the microscope — a curiously frayed appearance. The radii are very short, set 

 almost parallel with the ramus, and showing no more than traces of fila. They also 

 occur on the shaft in the internodes between the bases of the rami. 



A feather from the lower limb of the postaural fold shows the following points : — 

 The shaft is bent upon the calamus at a considerable angle in an upward and lateral 

 direction. The calamus is abruptly distinguishable from the scapus by its greater 

 thickness. The inner vexillum is roughly triangular in form, the base extending from 

 the superior umbilicus to the top of the stem ; the outer vexillum is much smaller and 

 also triangular, its base running from the upper umbilicus to the middle of the stem. 

 The rami are entirely disconnected and wadely separated. The radii are very short ; those 

 of the proximal series lie parallel with the ramus ; the distal radii are longer. Fila are 

 absent. Short radii run along the scapus in the interval between the rami. 



The feathers of the Loreal area are long, with fairly stiff, rigid axes. Rami 

 very short, degenerate, showing neither fila nor booklets, and decreasing in length on 

 each side of the ramus from the base upw'ai'ds, finally disappearing. They also run 

 along the internodes on each side of the shaft from the base of one ramus to that of the 

 next in front. 



Plmmilce. — In these the rhachis is relatively short as compared with the rami, which 

 are of great length. The radii are long, transparent, and divisible into segments — 

 nodes and internodes — by the deposition of pigment in the region of the fila. The fila 



