Vol. XV. 1 ^^jn^TFi;i.i)T, Osteology nf Ortliorhauiphus niai^Jiirostris. ly 



sharp anterior and a thickened posterior edge, the bone, as a 

 whole, curving from base to apex. It is pierced by a small 

 foramen at its postero-inferior angle, indicating the point between 

 the haemal spines of the otherwise indistinguishably fused eighth 

 and ninth caudal vertebrae. Unfortunately, the apex of this 

 pygostyle was broken off and lost when the skeleton was loaned 

 me, but it would appear to have been quite j^ointed. 



The neural spines of the first four caudal vertebras are short 

 and thick, while fairly well marked antero-posterior grooves at 

 their apices make them appear as though each were moderately 

 bifurcated. 



The neural spines of the last three caudals become gradually 

 more and more rudimentary as we proceed toward the pygostyle. 

 These last three vertebrae, however, possess haemal spines which 

 are lacking in the four preceding them. No chevron bones appear 

 to be present, and the diapophyses of all these caudal vertebrae, 

 save the ultimate one, are well developed, they gradually 

 becoming shorter and shorter as one follows them toward the 

 coccyx. 



The Pectoral Limb (figs. 12, 13, Plate VI.) — That this Stone- 

 Plover is a good flyer is evidenced by the bones of the skeleton 

 of its wings, and, although none of them enjoy pneumaticity — 

 not even the humerus — they are nevertheless strong, and possess 

 lengths in keeping with the balance of the skeleton. In the main, 

 they are all rather slender and straight, the shaft of no one of 

 them presenting any marked curvature, even the usual sigmoid 

 curves of the shaft of the humerus being much less evident than 

 in some birds representing other groups not intimately related 

 to the Limicolce or the Longipennes. By measurement I ascertain 

 the lengths of these bones to be as follows* : — ■ 



Humerus . . . . . . . . . . 102 millimeters. 



Radius . . . . . . . . . . 113 ,, 



Ulna . . . . . . . . . . 117 „ 



Carpo-metacarpus . . . . . . 50 „ 



Proximal phalange of index digit . . 22 ,, 



Distal one. . . . . . . . . . 21 ,, 



Phalange of pollex without the claw . . 14 ,, 



The caput humeri of the humerus is rather large and hemi- 

 ellipsoidal in form. To its radial side there is an extensive, flat 

 facet fn- the insertion of the pectoralis secundus muscle. f It 

 stands at the proximal termination of the radial crest. This 

 latter i an extensive process, bent palmad, its outline being 



* Shoul these measurements not agree with the figures in the Plate, 

 it may be due to the fact that they were not followed by the half-toners 

 in reproducing my photographs of the specimens. As submitted, the latter 

 were sligl y above natural size, in order to ensure sharpness in repro- 

 duction. 



t Shufeldt. R. \V., " Myology of the Raven," p. J2. A very full synonymy 

 of this muscle is here presented, made by Dr. Hans Gadow (Hronn's Klasseii. 

 VI. Band, p. 246). 



•2 



