No. I.] THE CRANIUM IN THE OWLS. 155 



also the os squamosum, inasmuch as it is here drawn out in 

 a greater degree laterally, and also more depressed than upon 

 the opposite side, in such a manner that the crest becomes 

 broader above, on the right side, and more tuberously swollen 

 than upon the left side. 



The orbits thus become a trifle wider, but at the same time 

 lower, than upon the left side. Upon the posterior aspect of 

 the apex of the osseous crest there is to be found a process 

 that is not especially conspicuous. 



The frontal region, posterior to the supraorbital processes, 

 is profoundly concaved,^ but, upon the whole, particularly 

 broad, and much broader than the surface in front of these 

 processes, which, relatively speaking, is also of considerable 

 width. Either frontal bone slopes obliquely downwards from 

 the middle of the cranium towards the hinder border of the 

 orbit, and is very deep posterior to the supraorbital processes. 

 If the cranium is seen upon direct posterior view, the supra- 

 orbital process of the right side, including its upper border, is 

 in view beyond the limiting profile line of the frontal, while 

 the left one is hidden behind it. The interorbital septum is 

 notably thick and of limited area, and this thickness is to be 

 found over its entire extent, and it is only just above the 

 rostrum of the sphenoid that there is to be found a thinner 

 place, which only in a very limited degree is semitransparent. 



The osseous crest of the squamosal bone is normal upon 

 the left side, having the same structure as in S. aluco and 

 vS. iiralense, forming there a supero-anteriorly directed process, 

 that is, above, perfectly free. This crest is particularly lofty 

 upon the right side, where it extends upwards and forwards 

 as a prominently curved apophysis that reaches to the upper 

 border of the os alisphenoides ; this latter is decidedly massive, 

 and, as has before been remarked, stands out from the side of 

 the skull in a most abnormal manner. The two processes do 

 not fuse at their point of contact, but are simply joined there 

 by membrane. The fossa formed by the osseous crest, the 

 entrance to which is in front, thus becomes more capacious, and 



1 I take this to refer to the superior orbital borders, they being roundly concaved 

 in most species of Syrnium, just behind the supraorbital processes. — R. W. S. 



