26 MR ROBERT B. THOMSON : SCOTTISH NATIONAL ANTARCTIC EXPEDITION : 



Carpal Bones. 



These were seven in number, the scaphoid and semilunar being fused together to 

 form a single bone. The carpal bones were devoid of ridges or processes. The articu- 

 lations were difficult to make out, but I have referred these as follows : 



The scapholunar articulated with radius, trapezium, trapezoid, os magnum, and 

 unciform. 



The cuneiform articulated with the ulna, pisiform, and unciform. 



The pisiform was a mere nodule, and articulated with the cuneiform and ulna. 



The trapezium articulated with scapholunar, trapezoid, and 1st and 2nd metacarpals. 



The trapezoid articulated with scapholunar, trapezium, os magnum, and 2nd meta- 

 carpals. 



The os magnum was small, and articulated with the 2nd, 3rd, and 4th metacarpals, 

 and with the trapezoid, scapholunar, and unciform. 



The unciform articulated with the scapholunar, cuneiform, and os magnum, and with 

 the 4th and 5th metacarpals. 



Metacarpal Bones. 



The 1st metacarpal was the longest, and possessed both a proximal and a distal 

 epiphysis not united with the shaft. The 2nd was longer than the 3rd, 4th, or 5th, 

 which were of about equal length, and the epiphysis for the head of each was separate 

 from the shaft. 



Jlie Hind-Limb. 



The innominate bone, measuring in length 215 mm., consisted of three parts ilium, 

 ischium, and pubis. The ilium was short and stunted. The ischium and pubis were 

 long, somewhat narrow, and enclosed between them a very large obturator foramen- 

 larger indeed than the ilium itself. 



The acetabulum was circular in form, entirely articular except an elongated, hollow 

 area at the bottom with a definite margin. The brim of the acetabulum was deficient 

 in its lower aspect, thus forming a cotyloid notch. The ilium measured from centre 

 of acetabulum to the highest part of the iliac crest 74 mm. The length of its crest was 

 102 mm. Its dorsal and ventral aspects were flattened and did not possess any definite 

 muscular ridges. At the posterior part of the ventral surface was a U -shaped articular 

 surface for that part of sacrum corresponding to its first segment, while there was a 

 roughened area for the attachment of the posterior sacro-iliac ligament. 



The os pubis projected backwards and slightly downwards from the acetabulum, 

 and its junction with the ilium was marked by a prominent pectineal eminence. From 

 this tubercle to the symphysis, which was small, the pubis measured 130 mm. 



The ischium passed backwards and slightly upwards from the acetabulum, and 

 possessed a pointed spine. 



The femur measured 114 mm. long. The head was entirely articular except in its 

 postero-superior quadrant, where there was a non-articular area continuous with the 



(ROT. soc. EDIN. TRANS., VOL. XLVII., 196.) 



