116 PLEISTOCENE MAMMALIA. 



compressed. The distal end can generally be recognised by the large perforation of the 

 inner condyloid crest at a slight distance above the articulation (figs. 1, 2 i). This 

 character, however, is also found abnormally in some few of the humeri of Bears that are 

 found side by side with Felis spelaa. The part, therefore, must be described minutely, 

 to prevent the two species from being confounded. Immediately below the deltoid ridge 

 the spelaean shaft is cylindrical, and then throws out the broad flat externo-condylian 

 (figs. 1, 2, m, e) ridge on the postero-external aspect that extends to the external condyle. 

 It affords insertions, as in Man, to the heads of the following muscles : anteriorly to the 

 extensor carpi radialis longior and brevior, the first and second radials, which are not 

 fused together as in Man ; posteriorly to the extensor communis digitorum, and laterally 

 to the supinator brevis ; superiorly to the supinator longus, and posteriorly and on the 

 inner side of the ridge passing diagonally upwards from the crest to the anconeus 

 externus. The condyles are of moderate size, the external (figs. 1, 2, 3 /) projecting but 

 slightly beyond the articulation, and the internal (figs. 1, 2, 3 /') being by far the more 

 prominent of the two ; it is, however, far less prominent than in the Bear, and proportion- 

 ally even than in Man. 



The internal condylian crest is, as we have before stated, pierced by a large 

 foramen (figs. 1, 2 ^), directed diagonally forwards and downwards for the passage of the 

 ulnar nerve and artery. The abutments, as it were, of the bony arch are generally found 

 in the Bears, and sometimes in the Hysena, the key of the arch in that case being formed 

 by a ligament. In the former animal, however, where the arch is completed by a deposit 

 of osseous matter, it is much nearer the distal end of the bone, and is much thinner than 

 in Felis spelaa. This diflPerence, together with the greater breadth of the distal end and 

 the large size of the internal condyle, will sufficiently distinguish the distal portion of the 

 humerus of Bear from that of the larger Feles. 



The anconeus internus is inserted on the posterior portion of the arch. The large 

 space occupied by the insertions of the three muscles bearing this name, indicates the 

 enormous power of extension of fore-limb, which enables the larger Feles to use their paws 

 with such destructive eff'ect. 



The external condyle affords insertions to the following muscles : the extensor minimi 

 digiti, and the external ulnar ; the internal to the sublimis, the pronator teres, the palmaris 

 longus, ulnaris externus, and profundus muscles. 



The articulation (figs. 1, 2, 3/,/') somewhat resembles that of the Bear, but it is 

 broader transversely and thicker, and the trochlear portion (figs. 1, 2, 3/, /, ^) is less 

 excavated. The latter is distinguished from the capitellar portion (figs. 1, 2, 3/, &) by the 

 transverse convexity of its surface. The internal bounding ridge (figs. 2, 3/') is sharp 

 and high, but less so than in the Bear. The postero-external (figs. 1, 3, 0) is very thin 

 and sharp, and shghtly undercut. The olecranal fossa (fig. Ijo) is of great depth and 

 size, especially on the external side, but the coronoid (fig. 3 d) fossa is hardly defined, the 

 surface of the shaft passing in an easy sweep to the edge of the articulation. The whole 



