4 Shufelut, Osteology of Oiihoi/uiiHphus magnirostris. [,^f"j"|.. 



spicuous supra-orbital glandular depressions ; they are quite unlike 

 those concavities as they occur in the skulls of any of the birds 

 before me at this writing, and, moreover, they differ widely from 

 what we find in Qbdicnemtts, in which latter form they are shallow, 

 well separated in the median line, curve outwards anteriorly, and, 

 finally, each depression terminates near the fronto-lacrymal 

 suture, on its own side, in a foramen of no great size. 



Now, in Orthorhampkus magnirostris these depressions meet for 

 their entire lengths in the middle ; they are unusually deep, being 

 rounded posteriorly and truncated in front, each terminating 

 anteriorly in a large, single elliptical foramen, situated between 

 the frontal and lacrymal bones. These are well shown in fig. 7 

 of Plate II., and it is to be observed that, laterally, these con- 

 cavities are far removed from the orbital margins, which is also 

 the case in the skull of (Edicnemus histriatus. In some true 

 Plovers, however, as is the case in Squatarola, these glandular 

 depressions are very shallow ; they meet mesially in the frontal 

 region, each to curve outwards behind, in which locality alone 

 they do not approach the orbital margins. Here the lacrymo- 

 frontal foramina are mere notches, while, as already remarked 

 above, a pair of foramina are found over the middle of the orbits, 

 one upon either side. (Compare figs. 16 and 18 of Plate VI.) 



In the Chilean Lapwing Plover {Belonopteriis chilensis, fig. 15, 

 Plate VII.), the character of these depressions is again entirely 

 different. Each consists of a distinctly defined, long, and narrow 

 concavity, with a single small foramen at the extreme anterior 

 end. A considerable interval separates them in the median 

 line, and each is very slightly curved, the concavity of which is 

 toward the sharp, free margin of the orbit. They are almost 

 identical in their morphology in the Kittiwake Gull {Rissa t. 

 tridactyla) and in the Black Oyster-catcher [Hmnatopiis niger), 

 where they are more or less shallow, meet in the middle line, 

 extend to the free peripheries of the orbits, and to the external 

 apices of the lacrymals. In Rissa they do not extend very far 

 posteriorly, while in the Oyster-catcher they are continued on 

 either side to the tip of the post-frontal process. We find their 

 characters the same in Lams glauciis and other Gulls, while in 

 Larus argentatus they are separated in the middle line (No. 18,204, 

 Coll. U.S. Nat. Mus.) (Edicnemus histriatus has them short and 

 broad, separated mesially ; and a single foramen is situated far 

 forwards in each of these shallow cavities (fig. 18, Plate VII.) 

 They are entirely different in Chionarckns minor, as is shown in 

 fig. 14 of Plate VII., and, as I have elsewhere shown, they depart 

 in their characters in this bird from any other form ever examined 

 by me in the entire Class Aves* 



* Shufeklt, R. \V., "Contributions to the Comparative Osteology oi 

 Arctic and Sub-Arctic Water-Birds," Part I., Journ. Anat. and Phys., Lond., 

 Oct., 1888, vol. xxiii. ; n.s., vol. iii., pp. 1-39, Plates I. -IV., 40 figures. 

 Many of the skulls here figured should be compared with the skull of Ortho- 

 rhampkus magnirostris. These " Contributions " ran through in nine parts 

 (Oct., 1888-91), and contain many descriptions and figures of skeletons of 



