REPORT ON THE SEALS. 47 



and articulated with the trapezium and second metacarpal. The 2nd metacarpal 

 articulated with the 1st and 3rd, and with the trapezium and trapezoid. The 3rd 

 metacarpal articulated with the 2nd and 4th and with the os magnum. The 4th 

 metacarpal articulated with the 3rd and 5th and with the unciform. The 5th meta- 

 carpal was only 56 mm. long, and was flattened, unlike the metacarpals of the other 

 fingers ; it articulated with the 4th metacarpal, the unciform, and cuneiform. The 

 metacarpal bone and phalanges of the minimus collectively measured 117 mm. The 

 nails were rudimentary, and the terminal phalanges ended abruptly and without an 

 ungual process. The skin, longitudinally wrinkled and without hairs, was prolonged 

 beyond the terminal phalanx, and in the pollex this cutaneous fold was 100 mm. long and 

 45 mm. broad. 



In Arctocephalus gazella the carpalia corresponded in number, shape, and arrange- 

 ment to the bones in Arctocephalus australis, but the} 7 were smaller. The bones of 

 the digits were also similar, but on a somewhat smaller scale. In both species the 2nd 

 phalanx of the minimus though wider was scarcely so long as the terminal phalanx. 

 Both in Arctocephalus gazella and the younger specimens of the Messier Channel 

 Arctocephalus, it was seen that the ossification of the phalanges and metacarpal bones 

 was on the same plan as in Macrorhinus and Leptonychotes. In Arctocepjhalus 

 gazella the length of the pollex and minimus was 178 and 89 mm. respectively. 



Pelvis. — This division of the skeleton consisted of the three sacral vertebras and the 

 two innominate bones. The length of the os innominatum was 210 mm., that of the 

 ilium 85 mm., and of the ischio-pubic part 125 mm. The ilium was more elongated than 

 is usual in the seals ; its dorsal surface was three times broader than the ventral, which 

 was 1 1 mm. broad, and was bounded externally by a rough surface for the origin of the 

 rectus ; the inner surface was as usual articular for the side of the sacrum, but the crest 

 of the bone instead of being in almost the same transverse plane as the base of the 

 sacrum, as in Macrorhinus and Leptonychotes, projected forwards, so that it was 31 mm. 

 in front of the base of the sacrum. Between the crest and the base of the sacrum the 

 inner surface of the ilium was marked for the origin of a muscle, probably the multifidus 

 spina?. The acetabulum had a complete covering of cartilage immediately within the 

 brim, but at the bottom of the cup was a narrow rough depression which opened at the 

 back of the brim in a small cotyloid notch or foramen. The margin of the brim was 

 complete in bone, as the cotyloid notch was bridged by a bony bar which almost 

 converted the notch into a foramen for the passage of the vessels and nerves into the 

 joint. The os pubis and ischium were slender bars of bone, and the symphysis was 

 limited to the junction of the two pubic bones. The junction of the os pubis and ilium 

 was marked by a very prominent pectineal tubercle, and the pectineal line was sharp. 

 The ischium had neither definite tuberosity nor spine, and the obturator foramen was 

 elongated. 



