Vol. XV. 



1915 



1 Shufkldt, Osteology of Orthorhamphus magnirostris . 



Either palatine is conspicuously developed, and when articulated 

 as in lite these bones do not quite come in contact in the middle 

 line. The postero-external angle is completely rounded off, while 

 up to a point opposite the lower end of a lacrymal, the inner and 

 outer edges of one oi these bones are turned ciownward, especially 

 the mesial edge. This creates a moderate concavity on the 

 posterior third of the bone : while beyond it they are flat, with 

 the lower or ventral surfaces somewhat inclined toward the mesial 

 plane. These bones make the usual articulations anteriorly, and 

 with the premaxillary and the maxillo-i)alatines ; and in the 

 skull of the adult nearly all the sutural lines are obliterated, 

 especially with the premaxillary in the root of the mouth. 



As well as I can judge from the mutilated skull of (Edicnemus 

 bistriatus at hand, its palatine bones agree quite closely with 

 those of Orthorhamphus, though anteriorly they may be some- 

 what narrower. With some slight modifications, they also agree 

 with the palatines as we find them in a great many of tlic 

 Limicolce, Longipennes, and their near congeners. (Fig. 5, 

 Plate in.) 



This agreement is also seen in the case of the viaxillo-palatines, 

 with the exception of the Oyster-catchers {Hcematopus), in which 

 genus, as I have previously shown, they are peculiar. In our 

 subject, a maxillo-palatine nearly meets the scroll-like portion 

 of the fellow of the opposite side in the middle longitudinal line, 

 the vomer being well above the narrow interval between them. 

 This interval is considerably wider in Larits, Hcematopns, and 

 most Plovers, and the vomer is more basally situated in them, 

 thus bringing it into plainer view when the skull is regarded 

 upon its ventral aspect. 



The maxillary in Orthorhamphus, upon leaving the zygoma, is 

 a thin, horizontal plate of bone ; when half-way across to the 

 scroll-like portion of the maxillo-palatine it bifurcates, and, the 

 mesial ends expanding, the superior branch fuses with the 

 superior margin of the scroll-like part, and the lower branch with 

 the inferior margin of the same. This arrangement is quite 

 different in Plovers, Gulls, Oyster-catchers, Turnstones, &c., as 

 in these the osseous connecting bridge of the maxillo-palatine, on 

 either side, is very short, and in some species quite inconspicuous. 



Unfortunately, the ossicula auditus have been lost in the case 

 of the skeleton of the species here being considered, so I cannot 

 describe them. On the other hand, the sclerotal platelets of both 

 orbits were saved (fig. 3, Plate III.) As is well known, the eyes 

 in this bird are of great size ; but these overlapping laminae of bones 

 present nothing peculiar beyond the fact that they are very narrow 

 in front, and gradually become wider and wider as we pass back- 

 wards, the posterior ones being markedly wider than those in 

 front. 



Passing to the mandible, we find it to be a bone presenting 

 some interesting characters. In form, it is of the narrow, acute 

 V-shaped pattern (fig. i, Plate II. : fig. 6, Plate III.), with deep 

 rami, and strong, bulky articular extremities. Viewed laterally. 



