DE. J. MUEIE ON THE ANATOMY OP THE SEA-LION. 515 



wide hollow ; the inner glides upon the radius ; a narrow comer of the anterior impinges 

 against the scapholunar, its remainder articulating with the unciform ; and an outer facet 

 partly accommodates the fifth metacarpal as the manus is twisted outwards. The 

 pisiform is a small bean-shaped bone, its free end directed outwards, its attached end 

 lying upon the epiphysis of the ulna and the cuneiform of the four articular surfaces 

 presented by the trapezium ; that towards the second metacarpal is a mere corner facet. 

 The trapezoidal is smaller than the trapezium, its palmar surface being very consider- 

 ably narrowed. It just touches the third metacarpal, besides its ordinary facets for 

 scaphoid, magnum, trapezium, and first metacarpal. The os magnum is the least-sized 

 bone of the distal row, and, reversely from the last, has a narrow dorsal and broader 

 palmar surface. It appears not to come into contact with the second metacarpal, and 

 sinks in obliquely and below the scapholunar. Thus when the manus is planted on the 

 ground the latter bone overrides it in great part. The unciform is about equal to the 

 trapezoides in magnitude. It is surrounded by five bones, the fifth metacarpal more 

 usually constituting its outer boundary. 



The metacarpals are of most unequal dimensions, that of the poUex being of inordi- 

 nate proportions. The lengths from 1st to 5th are as follows: — 4-25, 3, 2-3, 2, and 

 1-9 inch. The first is by far the broadest, thickest, and flattest; the thu-d thinnest and 

 roundest. The fifth difiers from the fourth in being a wider bone. The proximal ends 

 of the outer four are enlarged and tuberose ; the width of the innermost (first) subdues 

 its otherwise bulky character. 



The phalanges, of normal number, bear a relation to the size of the metacarpals ; that 

 is, the innermost is largest and longest, the fifth digit a trifle stronger though shorter 

 than the fourth. The proximal phalanx of the thumb is powerful, its distal one a short 

 flat figure of eight; respectively they are 3-9 and 1-5 inch long. The lengths of the 

 remainder of the series are: — second digit 2-7, 2-2, 1; third digit 1-9, 1-6, 1; fourth 

 digit 1-5, 0-8, 0.3; fifth digit 1-3, 0-3, 0-2 inch. The spatulate cartilages and that 

 extraordinary one of the pollex, which form the digital extremities, I drew attention to 

 and figured in my former anatomical contribution. 



b. Pelvic Limb.— Pelvis. The long axis of the entire pelvis is almost identical with 

 that of the spinal column, and even in the strange attitude of walking it accords with 

 the lumbo-caudal region'. Ilio-pubic and ilio-ischial angles cannot be said to obtain. 

 Each innominate bone approaches posteriorly so as to produce a long narrow V-shaped 

 pelvis, and with such variation in the thickness of the bones that the brim is lozenge- 

 shaped. The ischium and pubis are narrow bars uniting in a thin rounded plate the 

 tuberosity, and enclosing a lengthened oval obturator foramen. Their acetabular ends 

 thicken ; the acetabulum itself is large but not deep. The ilium is a broader strip of 

 bone, slightly outturned anteriorly, its sacral border intumed, and with moderate sacro- 



'■ Cuvier {I. c. p. 226) briefly distinguishes between the pelvis of the Earless and Eared Seals, a point which 

 Allen in his paper {I. c. p. 27) with justice lays great stress on as characteristic of the two groups. 



