MR. W, K. PARKER ON THE OSTEOLOGY OF BAL^NICEPS REX. 291 



the pre-maxillary, but the orbital margin of the lacrymal is turned outwards at a con- 

 siderable angle. This facial development of the lacrymal is like what we see in the 

 Crocodile, and still more fully in certain mammals, e. y. Bos, Ovis, Sus. In the 

 Albatros, a thin bone, broad above and pointed below, articulates with the lacrymal 

 near its base in front, and passes downwards to be attached by a ligament to the 

 palatine. In Eagles, Falcons, and Hawks, a small supra-orbital is articulated to the 

 long outstanding process of the lacrymal, and helps to give them their peculiar frowning 

 aspect. This supra-orbital is seen again in certain Crocodiles, and also in some fishes, 

 e. g. the Carp. That the lacrymal is not a dermal bone (as Professor Owen says), but 

 'an actinapophysis of the ethmoidal neural arch,' see Professor Goodsir's arguments 

 in the work already referred to (p. 152). This far-seeing anatomist's writings will not 

 admit of condensation. If the lacrymal of the bird should turn out to be a ' prefronto- 

 lacrymal',' then Professor Goodsir's views concerning the next bone, the ' nasal' of 

 authors, will be seen to be mistaken. 



Nasal or " Ethmoido-frontal." (PL LXV. figs. 1 & 6, n.) 



As a rule, those cold-blooded oviparous vertebrata with horny toothless jaws (the 

 Chelonia) have no distinct nasals. Professor Owen, who stands unrivalled in osteolo- 

 gical experience, has, we believe, seen only three exceptions, — e. g. in the recent 

 Hydromedusa, and in the fossil Chelone planiceps and pulchriceps (see ' Rep. on Archet.' 

 p. 224). 



The views of Professor Goodsir upon this very difiicult subject deserve the most 

 attentive consideration ; and it is possible that even in the whole class of Birds there 

 may be no distinct 'nasals;' in that case, that down-turned broad surface of the 

 ethmoid, in such birds as the Vulture, the Hawk, and the Parrot, which, becoming 

 ossified, converts the nostril into a small round anterior opening, would be an exogenous 

 nasal. The nasal of the bird, however, has no descending antorbital process bounding 

 the olfactory nerve externally, for the antorbitals of the bird belong to, or coalesce with, 

 the sclerotome next behind. Perhaps the ' pre-frontals ' continue membrano-cartilagi- 

 nous in birds, or the so-called ' nasals ' represent their upper and outer surface ; or the 

 lacrymals may be compound in their nature, although this is very unlikely ; for it 

 seems to us that the only ossified part of the prefrontal of the bird is the autogenous 

 antorbital. 



In those birds which have a broad nasal with its bifurcations widely apart, e. g. the 

 Rook and the Fowl, the nasal fossa is oval, the anterior bifurcating margin of this bone 

 being its posterior boundary ; where the bone splits itself sharply, e. g. the Crane and 

 Plover, the nasal fossa is of necessity angular behind. 



In Fowls and Ostriches, the pre-sphenoid appears on the roof between the nasals and 

 sphenoido-frontals ; but in most birds these bones form a very perfect covering to this 

 ' This is evidently the case when it coalesces with an autogenous antorbital process. 



