86 PEOCEEDINGS OF THE NATIONAL MUSEUM vol. T3 



femur. Murie stated that in Ewnetopias origin was from the sacral 

 vertebrae, which seems unlikely. 



M. obturator internus (figs. 12, 16) arose from the inner border of the 

 obturator foramen and its membrane, passed over the dorsal border 

 of the ischium between and in close association with the two gemelli, 

 and inserted by the usual tendon into the trochanteric fossa of the 

 femur. 



M. gemellus inferior (figs. 11, 12, 16, 24) in both animals arose from 

 a similar area upon the dorsal border of the ischium — roughly the 

 second quarter of the distance from the acetabulum to the caudal 

 border. In the Phoca, however, there was in addition a strong 

 tendon arising from the bicipital process and disappearing in the 

 substance of the muscle. In the ZoIopJms insertion was upon the side 

 of the greater trochanter, between the obturator internus and quad- 

 ratus femoris. At first glance it seemed to be a part of the latter 

 muscle. In the Plwca its tendon joined the insertion of the obturator 

 internus. For Ewnetojyias insertion was given as between the greater 

 and lesser trochanters. MiEer referred to this muscle in parts of his 

 text but did not describe it. 



M. quadrattts femoris (figs. 11, 12, 16) in the Zalophus arose from the 

 dorsal half of the caudal border of the ischium, bounded dorsad by 

 the gemellus inferior, ventrad chiefly by adductor 1, and mediad by 

 the obturator externus. Insertion was along the entire latero-caudal 

 border of the femur. In Arctocephalus insertion was said to be upon 

 the "lower half of the posterior border of the great trochanter.'' 

 For Eumetopias Murie gave insertion as the outer side of the lesser 

 trochanter. The muscle is absent in the Phocidae. 



M. obturator externus (figs. 11, 12) in the Zalophus arose not just 

 from the border of its foramen, but from a considerable area of bone 

 caudad and ventrad, and from all but the dorsal part of the obturator 

 membrane. Insertion was tendinous near the disto-caudal part of the 

 greater trochanter. In the Phoca origin was much more restricted. 

 It arose from the obturator membrane only over its dorsal and 

 cranial parts, from the bone anterior to the obturator foramen, and 

 from the dorso-cranial part of the pubis, the latter part of the muscle 

 having almost the appearance of a separate slip. Insertion was par- 

 tially tendinous into the obturator fossa of the femur. In Eumeto- 

 pias insertion was said by Murie to be onto the lesser trochanter, 

 while in Mirounga insertion was upon the greater trochanter ; but in 

 this Miller was probably mistaken, as he was, at least for P. hispidn, 

 when he stated that the adductors are absent in the Phocinae, for the 

 adductors constitute the ectal part of his obturator externus, and he 

 evidently missed the deeper and very small latter muscle. 



