6 Shufeldt, Osteology of Orthorhamphns magnirostris. [,sf"|ui,, 



Oyster-catchers {HcBmatopvts) have their lacrymal bones very 

 much as they are in certain Laridce, though their upper portions 

 project more prominently, and the descending hmb of either of 

 these bones is much stouter, making a more extensive union with 

 the side of the pars plana. As viewed from above, this agree- 

 ment is well shown in figs. 17 and 19 of Plate VII. of the present 

 paper, and there, too, will be seen, on the same aspect, the 

 lacrymals in Chionarchus, Squatarola, and others, each and all 

 of which I have described in former osteological papers. 



One of the most interesting features of the skull in these big. 

 Plover-like birds is the superior mandible (fig. i, Plate II. ; 

 figs. 5 and 6, Plate III. ; fig. 18, Plate VII.) Measuring along 

 the culmen, from the cranio-facial hinge to the apex, in Ortho- 

 rhamphus, it is seen to have a length of 7 centimeters, whereas this 

 same length in G^dicnenius bistriatus measures but 5.3 centimeters. 

 In both skulls the narial apertures are large and elongo-elliptical 

 in outline, while both differ from all the true Plovers, Gulls, 

 Oyster-catchers, and numerous other limicoline and larine species 

 in being holorhinal birds, and not schizorhinal ones. The 

 holorhinal conformation of the nasal bones, in the case of 

 CEdicneimis, has long been known, and on that account probably 

 suspected in the case of Orthorharnphiis, though the fact has not 

 heretofore been published.* 



In Orthorharnphiis, the superior mandible is not only of large 

 size, very long and tapering, but it is likewise somewhat decurved, 

 with rounded culmen and cultrate tomia. Most Plovers, on the 

 other hand, have the upper mandible and the dentary portion of 

 the jaw nearly straight, with the narial openings extended to 

 within a short distance of the apex in the upper bill. This is the 

 case with a good many of the Limicolce. 



Turning to the basi-cranial region of the skull of the bird here 

 being considered, it is at once apparent that in all of its general 

 characters it far more closely resembles the corresponding part 

 of the cranium in an average Gull — Larus argentaius, for example 

 — than that of any Plover that I have ever examined or com- 

 pared it with. Indeed, all this part of the cranium in Ortho- 

 rharnphiis is almost typically larine in its morphology. 



Most all Plovers [Squatarola, &c.) have present the " supra- 

 occipital foramina," one on either side of the supra-occipital 

 prominence. These are small in the Chilean Lapwing, but of 

 good size in the Golden Plover and others. In Orthorhamphiis 

 they are entirely absent. 



* Forbes, W. A., "Coll. Sci. Mem.," pp. 189-213, figs, i and 2. This 

 talented avian anatomist, who died at Shonga, Africa, many years ago 

 (ist January, 1883), here says that "Birds belonging to the schizorhinal 

 group are nearly all, with the exception of Platalca and Ibis, ' schizognathous ,' 

 as regards their palate. The ' Schizorhince ' comprise the following minor 

 groups : — ColnmbidcB, Pterochlides, TurnicidcB, ParridcB, LimicolcB (except 

 CEdicneimis, which is holorhinal, herein agreeing with the Bustards), Laridce, 

 Gruides, Eurypygides, Rhinochetides, PlataleidcB (the Hemiglottides of Nitzsch), 

 and AlcidcB." He also pointed out that Mcsites and all the RaUidcp are 

 holorhinal birds. 



