REPORT ON THE SEALS. 185 



flexion of the leg only takes place in the Phocinas when on land, but this muscle will be a powerful 

 depressor of the hinder extremity in the water. In the Phocime it is supplied by a branch of the 

 deep anterior crural nerve. 



The Internal Femoral Region of the Phocina? and Macrorhinus Iconinus contains the pectineus, 

 obturator externus, adductor longus, and adductor brevis. 



In Arctoccphalus gazclla there are in addition the pectineo-superficialis vel femoralis, and adductor 

 magnus. 



The Pectineus in the Phocinse is triangular and of small size. It arises from the ventral surface 

 of the pubic bar behind the ilio-pectineal eminence ; and slightly from the inner side of the bar. The 

 psoas tertius crosses it and the obturator is above it. It passes across the head of the femur to the 

 inner side of the posterior surface of the shaft ; and is inserted into the capsule, and into the upper 

 third of the inner surface of the back of the femur, extending across the femur one-half its breadth. 



In Macrorhinus leoninus it arises from the posterior third of the ilio-pectineal eminence outside 

 the pelvic brim, from the anterior quarter of the pelvic brim, and slightly from its outer surface, 

 reaching as far as the capsule of the hip-joint. It passes downwards over the capsule, and is 

 inserted into the upper third, and the inner half of the hinder surface of the femur. If a line be 

 drawn from the middle of the inner border of the femur to meet the upper third of one drawn 

 through the centre of the long axis over the back of the shaft, the attachment is into the triangular 

 space below the neck inside the lines indicated. 



In Arctoccpludus gazclla it is called "adductor brevis primus" by Murie. It arises from one- 

 sixth of the ventral surface of the pubic bar, this part bemg ventral to the acetabulum and posterior to 

 the pectineal eminence. It is covered at the origin by the pectineo-superficialis vel femoralis, and is 

 inserted, after crossing the capsule of the hip-joint, into the back of the femur behind the small 

 trochanter. 



The Pectineo-superficialis vel femoralis is the same as the pectineus in Otaria and 

 Trichcchus. Upon the surface of the origin of the pectineus there is a band of fibres forming 

 a distinct muscle, which goes to the lower end of the inner side of the shaft of the femur. 

 It arises from the same sixth as the latter, but only from the crest of the os pubis, which 

 is to the inner side of the pectineal origin. It is inserted above the internal condyle of the 

 femur, at the junction of the front surface with the inner. This muscle may be looked upon 

 as an accessory psoas, and may be named pectineo-femoralis, for the insertion is similar to the 

 ilio-femoralis posterior in Macrorhinus. The pectineo-superficiabs is regarded as the pectineus in 

 Otaria and Trichcchus. It is an adductor. The superficiabs can flex the hip in addition. In 

 the Phocinae it is supplied by the obturator nerve. 



The Adductors are wanting in the Phocinae, but seem to be worked into the fibres of the very 

 large obturator externus. 



The Adductor longus in Macrorhinus Iconinus arises from the posterior outer half of the pubic- 

 bar, from the outer surface of the ascending ramus of the pubis, with the exception of a margin 

 near the symphysis, extending to the junction of this ramus with the descending ramus of tin- 

 ischium, which is in a line with the middle of the acetabulum, and very slightly from the 

 obturator membrane next the bone. It is inserted into the supracondyloid ridge below the psoas 

 tertius, and above the epiphysial line on the inner border of the femur. 



(ZOOL. CHALL. EXP. PAKT LXVIII. — 1888.) Yyy 2-1 



