82 PROCEEDINGS OF THE ITATIONAL MUSEUM vol.73 



M. supinator longus (figs. 9, 10, 20, 21, 23) in the Zalophus was spe- 

 cialized. Origin was from the more caudal portion of the lateral 

 shaft of the humerus extending quite to the head and partially be- 

 tween the brachialis and triceps. This excepts the deltoid crest, from 

 the distal termination of which arose but a few fasciculi of this 

 muscle. It then passed between the brachialis and extensor carpi 

 radialis and was joined by the more distal part of the deltoid. Its 

 tendon was inserted upon the most prominent part of the radial 

 aspect of the distal termination of the radius, just deep to the tendon 

 of the extensor metacarpi poUicis. In the Phoca origin was much 

 more restricted and more caudad, and there was no connection with 

 ihe deltoid. Murie stated that in Eunietopias this muscle had two 

 heads, the second from the deltoid crest, but I judge that there 

 was little difference from conditions in the Zalophus. From the 

 description of Arctocephcdus the origin in this animal was more 

 extensive. 



M. supinator brevis (figs. 9, 10, 20, 21) had its usual complex origin, 

 chiefly from the capsule of the elbow joint, but also upon the lateral 

 condyle of the humerus as indicated. (Fig. 9.) Insertion in both 

 animals was upon the cranio-lateral part of the radius from its head 

 to the pronator teres angle. 



The short muscles of the manus of these two families of pinnipeds 

 were adequately investigated by Murie and Miller, and as they are 

 not particularly pertinent to the present report, thej^ are here omitted. 



MUSCLES OF THE POSTERIOR LIi\IF, 



MUSCLES OF THE HIP 



The hypaxial muscles or psoal complex presented no especial diffi- 

 culties in Zalophus, but in the Phoca they were extremely closely 

 associated, peculiar, and withal so tender that nice dissection was 

 entirely out of the question. Miller found these muscles different 

 in each pliocid which he dissected, his descriptions are too involved, 

 and at least one error is indicated, for his magnus did not go to the 

 limb. His contribution is therefore of slight aid in this respect, nor 

 am I able to honiologize things eiitirelj^ to my own satisfaction. 



M. psoas minor (figs. 11, 24) in the Zalophus was rather small and 

 arose apparently from all the lumbar vertebrae, but craniad the asso- 

 ciation with the quadratus lumborum was so close that one can not 

 distinguish between the two muscles with certainty. A very slender 

 separate head also arose from the centrum of the last lumbar, joining 

 the remainder by a small tendon. The whole becaine stoutly tendi- 

 nous and inserted upon the pectineo-psoni process of the innominate. 

 In the Phoca the part that indubitably represented this muscle was 



