54 



MR. W. P. PYCRA.FT ON THE 



[May 2, 



data to support this interpretation. But the facts, in so far as they 

 ai'e relevant to the present paper, seem to show that the primitive 

 (archicentric) condition is represented fairly well in, say, Paradisea. 

 In Gorvus corax the longus poi'tion is degenerate and fuses Avith 

 the brevis just below the middle of the shaft of the humerus, the 

 brevis portion then running downwards, ultimately becoming 

 tendinous and passing to its insertion at the base of the ectepi- 



Text-fig. 15. 



C^ ?^, /. 



07.. 



Cv. 7^?.. C. 



Dissection of arm, dorsal aspect, of Eurtjlcfmus uchromelas, to show the deltoidens 

 major longtis and brevis. The longus portion has been cut through the middle, 

 and the two halves drawn in opposite directions. The brevis portion has now 

 beeonie very degenerate and quite functionless. 



d.m.h., deltoideus major brevis; d.m.l., deltoideus major longus; 

 a., anconeus ; h., humerus : n., nervus radialis. 



condylar process. In 6'turnus both portions are extremely A\-ell 

 developed, and perfectly separate until the distal end is attained, 

 where they^ fuse in a fleshy insertion in which may be traced two 

 distinct incipient tendons. 



