( 124 ) 



In tlie form of the tympanic cavitj' Palaeocorax agrees very closely with that 

 of the Raven ; indeed it seems to differ only in tliat the processus articularis 

 sijtiamosi is less sharply defined. In hoth, it is to be remarked, the lateral occi])ital 

 wing which bounds this cavity posteriorly sweeps ronnd sharply into the base of 

 t\\e processus zyyomaticiis srpifimosi, and anteriorly terminates beneatli the recessus 

 tijmpanicits anterior. 



The basi-temporal plate in Pdlaeocorax differs from that of the Raven, and 

 apparently C'orvidae as a whole, it may be remarked, in tliat it terminates in a 

 slightly raised free border, or, more accurately, in a slightly deflected edge, instea<l 

 of fusing with tlie basisphenoid. Vestiges of basipterygoid processes are slightly 

 more marked than in other Corvidae. The parasphenoidal rostrum is relatively less 

 swollen at its base than in the Raven. 



Tlie antorbital plate and lachrymonasal fossa agree exactly with those of the 

 Raven, save only that the external lateral border is relatively shorter than in the 

 Raven ; thus the free edge of this plate is but little longer than the base thereof 

 at its fnsion with the interorbital septum, while in the Raven, and Coreultur, 

 for examjile, this free edge is considerably longer than the width of the base. 

 The interorbital fenestra is actually, as well as relatively, larger than in the 

 Raven. 



So far, it will be remarked, no very striking characters have been pointed out 

 whereby the skull of Palaeocorax may be readily distinguished. If, however, the 

 palate be examined, it will at once become evident that the skull of this bird may 

 be distinguished from all other Corvidae. lu the first place the palate is almost 

 completely roofed in, only a narrow arcuate space being left in front of the vomer. 

 This condition of affairs is due in part to the ossification of the inferior border of 

 the nasal septum, and in part to ossification of the olfactory cartilaginous capsule. 

 A further contribution to this roofing is made by the maxilla, which is less reduced 

 than in other Corvidae, in tlie matter of its palatine extension. The maxillo- 

 ]iiilatine processes are also larger actually, as well as relatively, than in the Raven ; 

 furthermore "they are connected with the main body of the maxilla by a very short 

 and wide, instead of a long and slender stem : the difterence in length, however, is 

 accounted for by the backward extension and great breadth of the maxillo-palaliue 

 itself 



The vomer is unnsually large, exceeding that of the Raven in width. On the 

 form of the vomer alone, indeed, Palaeocorax may readily be distinguished from all 

 the other Corvidae. The peculiarity in shape lies in this : that, seen from below, it 

 terminates anteriorly in abroad, flat, donble-scalloped edge, instead of in a U-shaped 

 notch whose sides are bevelled. Seen from above it will be noticed that the lateral 

 in-turned plates which spring from the sides of the body of the vomer are bent over 

 so as to overhang its dorsum at a sharp angle, whereas in the Raven these plates 

 take rather the form of high scrolls, rising at right angles to the horizontal jilaue 

 and having a semicircular section. Into the trough thus formed the nasal septum 

 is received. 



The nasal septum in the Raven, and perhaps the majority of the Corvidae, is 

 cartilaginous, but in Palaeocorax it is almost com])leteIy ossified. The cjnadratcs 

 and pterygoids are unfortunately missing in Palaeocorax. The ]ialatines diflVr in 

 no essential particulars from these rods in the Raven. 



Finally, the anterior nares in Palaeocorax are relatively smaller than in the 

 Raven. 



