ShUKELDT : OSTKOLOGY OK THE HeRODIONES. 22.S 



same time thick with very little curvature to it. Its distal end is 

 bluntly pointed, and it makes an extensive articulation with the cora- 

 coid, affording at the same time rather more than a third of the 

 glenoidal cavity for the head of the humerus. Apparently its anterior 

 moiety is pneumatic. A ^vr^/<vvV/ possesses a well-developed and curl- 

 ing clavicular j)rocess, while the upjjer end of the bone is laterally 

 much compressed, and correspondingly deep in the antero-posterior 

 direction. Its summit is moderately enlarged, being nearly smooth 

 and convex on top, and rises above the clavicle when the elements 

 are duly articulated. With respect to its shaft, we find it to be ellip- 

 tical upon horizontal section, it being somewhat compressed in the 

 direction from before backwards. As usual the sternal end is ex- 

 ])anded. and only a rudiment of an epicoracoidal process is |)resent. 

 The mesial angle of this end of the bone is sharply pointed, the con 

 vex portion of the sternal facet running clear out to the end of this 

 point on its under side. The sternal facet is continued as a concave 

 surface over a lip-like elevation of bone, nearer the middle line, low 

 down on the posterior aspect of this expanded end of the coracoid. 

 No foramen is seen to pierce its shaft, as in Plegadis guaraiaia, while 

 several sizable pneumatic foramina always occur on the inner surface 

 of the bone below its anterior summit. 



Of the Appendicular Skeleton. — Tantalus has an arm -skeleton of fine 

 proportions, being at the same time well built and strong. In it the 

 Jiunierus is the only bone enjoying jmeumaticity, the others lacking 

 that character entirely. AVith regard to the proportionable measure- 

 ments of these bones we find that the humerus has a length of 17.7 

 cm.; the radius 21.8 cm.; the ulna 22.8 cm.; the carpo-metacarpus 

 10.6 cm.; the proximal joint of index digit 4.4 cm.; the distal joint 

 of the same finger 3.4 cm.; and the pollux phalanx 3. i cm. No claws 

 are found upon the fingers, and the small phalanx of medius digit has 

 a length of 2.1 cm. 



Viewed upon either direct aspect the humerus presents the usual 

 sigmoidal curves, and its smooth shaft is elliptical on transverse mid- 

 section. The radial crest (^crista superior) is rather long, triangular 

 in form, with its free border not sharp. Conspicuously develo|)ed, 

 the ulnar crest {crista inferior) surrounds a capacious pneumatic 

 fossa, but the air hole is not especially large, is single, and situated on 

 the extreme mesial side of the fossa, near the middle line of the long 

 axis of the shaft. The fossa seen between the smooth demi-ellipsoidal 



