1()6 Annals of the Carnegie Museum. 



extent shown in Fig. 2. All traces between the nasa/ and contiguous 

 bones have been absorbed, still such is the conformation of the skull, 

 that one could predict with no little certainty, where their original 

 sites were. Coues (Key, 2d Ed., p. 647) states that the "nasal 

 bones are typically holorhinal " in the Herons, and so they are, ac- 

 cording to the rule laid down by Garrod for deciding that question, 

 that is, where "a transverse straight line drawn on the skull from the 

 most backward point of the external narial aperture of one side to 

 that of the other, always passes in front of the posterior terminations 

 of the nasal processes of the premaxill?e." (P. Z. S., 1873, p. 35.) 

 This rule, perhaps, will hold better as a guide, than the form the nasal 

 l)one assumes, for in this Heron there is an evident tendency on the 

 part of its nasal towards schizorhinalism, its posterior narial margin, at 

 least, being evidently distinctly angular, more so even than in Daption 

 capefisis, the skull of which Garrod figured, and which seems to have a 

 similar tendency. So far as form is concerned, I observe the typical 

 holorhinal skull in the GallincE generally — where the above noted rule 

 also holds equally good. 



Such single characters are of great service sometimes, to assist merely 

 in determining a bird's position in the system, but it is hard forme to 

 see how one could think of basing a classification upon such a trivial 

 condition any more than we could upon the shape of the beak itself. 

 Moreover, it would be of little use in such forms as Sula, where there 

 is no nostril present, and certainly it would in some cases violently 

 separate forms that in their general structure closely approach each 

 other. 



We find upon lateral view in Ardea herodias, a subelliptical aperture, 

 that is bounded anteriorly by the nasal, posteriorly by the lacrymal, 

 and below by the maxillary. Through it can be seen the upper parts 

 of the maxillo-palatinest The lacrymals in this Heron are very large 

 bones (Fig. 2) ; and the manner in which one articulates superiorly with 

 the frontal and nasal has already been noted above. Anteriorly, the 

 bone has a regularly concave margin, which bounds the aperture 

 alluded to in the preceding paragraph. Below, a lacrymal rests 

 rather more than its anterior half upon the maxillary, then is slightly 

 raised above it to project backwards as a process with a transversely 

 notched tip. Above this part of the bone there is a constriction which 

 divides it from the larger and upper portion. The surface is smooth 

 and the bone is highly pneumatic, air gaining access to its interior 



