"igis J Shvfeldt, Osieolof>y of OytJioi'hamp/ius maj^iiirostris. 15 



A ((Macoid has a height of 4.5 cms. ; a scapula a length of 

 ().2 cms., measured on the chord of its arc : the distance between 

 the free extremities of the os furculum is 2.5 cms., measured 

 within their arch, opjwsite the heads of the coracoids. 



From the above description it will be seen that in its pectoral 

 arch OrUioyliamphiis agrees with some of the ty])ical Plovers and 

 their near allies, as Squatarola. LobivaiieUiis Inhaliis. and others, 

 wherein the scapulae are long, those bones being much shorter, 

 relatively, in the Lapwings. 



The character of the pectoral arch in the Laridce presents a 

 nmnber of points not found in the limicoline species mentioned, 

 a prominent one being a " shoulder " on the outer aspect of 

 either free end of the 05 furcuhiin. 



In Chionarchiis minor a coracoid is almost the counterpart of 

 that bone in Rissa tridadyla ; the os furculum is thin and flat, 

 and. although U-shaped, has a form peculiar to itself. The 

 scapula has both pluvialine and larine characters in it. 



Pelvis and Coccygeal VertebrcB (fig. 8, Plate IV. ; figs. 9 and 10, 

 Plate V.) — Apart from such characters as it presents which are 

 sui generis with respect to this species, the pelvis of Oythorhamphits 

 inagnirostris is distinctly in agreement with that bone as we find 

 it in the skeletons of average Plovers and some of their allies. 

 It is a different style of pelvis altogether from what we find in the 

 Laridcv, in so far as I have examined the osteology of that 

 family. 



Anteriorly, the ilia are broad, much concaved and spreading, 

 with their anterior margins rounded and finished off with a raised 

 rim (fig. 9). Mesially they are, for a distance of about 2 cms., 

 in close contact with the neural crest of the fused vertebrae of the 

 anterior portion of the pelvic sacrum. Posterior to this contact, 

 the ilia again diverge from each other at rather a smart angle, 

 forming, as they do, the outer wall on either side to the posterior 

 entrances to the " ilio-neural canals."* 



Viewed upon lateral aspect, it will be observed that the cotyloid 

 cavity or acetabulum of this pelvis is relatively of small size, and 

 that the foramen at its base measures but 4 mm. in diameter. 

 There is a small prepiibic process present, and the antitrochanter 

 is small and faces almost directly forwards. Posteriorly, the 

 "obturator foramen" is very open; indeed, this foramen and 

 the large " obturator space " behind it form, in this pelvis, prac- 

 tically one vacuity (fig. 8). Above it, anteriorly, the ischiadic 

 foramen is large and of a broad elliptical outline. 



Beneath the obturator space, the post-pubic element is narrow, 

 thin, and curved, until it comes in contact for about 5 millimeters 

 with the infero-posterior angle of the ischium, after which it 

 slightly broadens, curving mesiad to terminate in a deep, free 

 point behind. Laterally, the ischium is broad and smooth ; 

 projects very considerably beyond the end of the consolidated 



* Owen, Sir Richard, " Coinp. .Vnat. and Phys. ot X'frls.," vol. ii., p. 32. 



