PROF. OWEN OlST ARGILLORNIS LONGIPEIOITS. 125 



meaning " toward the proximal end " and " toward the palmar side " 

 of the bone. 



In the proximal end of the humerus, figured in Plate VL, the 

 following parts are noted : — 



a. Articular head. 



b. Eadial tuberosity (answering to the " greater tuberosity," or tubercuhm 



majus. of anthropotomy). 



c. Ulnar tuberosity ("lesser tuberosity," or tuberculwm minus of anthro- 



potomy). 



d. Scapular groove, lodging the lower border of the glenoid surface of the 



scapula (part of the " neck of the humerus" of anthropotomy). 



e. Ligamentous pit or surface, receiving the anterior coracoid ligament. 

 /. Subtuberous fossa, with " foramen pneumaticum." 



g. Eadial border of ditto. 



h. Tricipital ridge. 



i. Pectoral crest. 



Jc. Ancono-deltoid ridge. 



I. Distal radial border of humerus. 



m. Prebrachial depression, 



n. Ectepicondylar process. 



The subject of figs. 1-3 includes, of the left humerus, the articular 

 head (a), the base of the radial tuberosity (6), that of the ulnar tu- 

 berosity (c), with the intervening scapular groove (d), the beginning 

 of the tricipital crest (A), and that of the pectoral crest (i). In what 

 remains of the subtuberous fossa part of a pneumatic foramen (/) is 

 preserved ; a greater proportion of the pneumatic fossa is shown in 

 the right humerus (fig. 3, /'). 



The head (fig. 3, a), or proximal articular surface, is, as usual, elon- 

 gate and moderately convex in the radio-ulnar direction, more convex 

 across the shorter ancono-palmar diameter. It is characterized by 

 its large relative size as compared, for example, with that in the 

 albatross (Diomedea exulans), ib. figs. 4-6 ; and differs from the hu- 

 merus in that and other birds in the degree and extent of the con- 

 cavity longitudinally, or in the direction of the long axis (fig. 3, a') 

 at the radial third part of the surface. The humerus of the Mara- 

 bou (Ciconia marabou, Temm.) offers a feeble approach to this 

 character. 



The radial or outer tuberosity (6) has lost its outer layer ; the 

 cancellous structure is exposed by abrasion. The rising or smooth 

 ridge (fig. 2, h), continued from the anconal part of the tuberosity 

 upon the shaft below, is better marked than in Vultur monachus, 

 still more so than in the marabou, pelican, and albatross, in which 

 it is barely definable. The ulnar or inner tuberosity (c) is bent 

 anconad, leaving a (scapular) groove or canal (d) between it and 

 the head, wider and shallower than in the vulture, marabou, crane, 

 and pelican, but less wide and shallow than in the albatross (fig. 4, d). 

 Of the shape and extent, however, of this tuberosity the worn and 

 fractured state of the fossil prevents a judgment. 



The palmar part of the head (fig. 1, a), though abraded, projects 

 further over that surface of the shaft than in any other bird with 

 which I have compared the fossil. In the extent of the flat ex- 



