88 PROCEEDINGS OF THE NATIONAL MUSEUM vol.73 



indeed a very remarkable muscle, origin extending from the spine 

 of the second to that of the seventh caudal vertebrae. The fibers 

 extended caudo-laterad to a tough sheet of aponeurosis covering the 

 side of the lower leg and stretching from the outer condyle of the 

 femur, the adjoining part of the tibia, and to the distal extremity 

 of the shank. In Ewmetoyias and Odoheiius origin Avas a trifle 

 farther caudad. A posterior head was very narrow and arose under 

 the caudal border of the main muscle, but its insertion was merely 

 a distal continuation of that of the main mass. This may be the 

 muscle termed by Murie a levator ani. The socalled short head of 

 the biceps was but a couple of centimeters in width and arose partly 

 from the transverse process of the second sacral vertebra and partly 

 from the sacro-iiiac ligament. It inserted upon the aponeurotic sheet 

 investing the dorsal border of the distal fibula. 



In the Phoca the biceps occurred in two divisions. The super- 

 ficial arose by a strong, tendinous origin from the dorsal spine of 

 the ischium. It spread fanwuse to a fascial insertion over the proxi- 

 mal seven-eighths of the lateral part of the tibia. It is thus seen 

 that in the ZaJojihus this muscle was in the form of a parallelogram, 

 closely binding the shank to the vertebral column, while in the 

 Phoca it w^as in the form of a triangle with pivotal apex upon the 

 ischium, theoretically permitting much more freedom of movement. 

 The deep division of the biceps of the Phoca was narrow and strap- 

 shaped, with fleshy origin from the transverse plate of the third 

 sacral vertebra, and aponeurotic insertion over the distal fibula. 

 This corresponds with the short head of Zalo'phus. 



Murie termed the short head in Eumetopias the sacro-peroneus, 

 and Lucae designated the heads as ischio-tibialis and sacro-fibularis. 

 In Arotocephalus there were three divisions, much as in Zalophus. 



M. sartorius (figs. 11, 12, 13, 16, 17, 24) in the Zalophus occurred in 

 two distinct slips. The proper one was very slender, arising from the 

 ventral angle of the iliac border with insertion upon the medial 

 patella partly deep to the tensor fasciae. The second arose from the 

 cranial part of the ventral border of the ilium and had fascial inser- 

 tion upon the medial tuberosit}?^ of the tibia mediad to and continuous 

 with that of the first division. In the Phoca it was single, arising 

 from the ventral angle of the ilium wdth insertion upon the patella 

 continuous with and mediad to the insertion of the tensor fasciae. 

 Miller reported it as single in Phoca and double in Arctocephalus^ 

 and Murie found it single in Emnetopias and Odohenus. 



M. rectus femoris (figs. 11, 12, IC, 17, 24, 25, 26) was a robust muscle 

 arising from the femoral process of the ilium cranio-ventrad of the 

 acetabulum, which is prominent in Zalophus but indicated only by a 

 roughened area in the Phoca. Insertion was upon the patella deep to 

 the sartorius and tensor fasciae femoris. 



