272 C. H. HURST, PH.D. 



I. 8 + 20 + 11=39 mm. 

 II 27-5 + 15 + 19 + 13 = 74'5mm, 



III. 26 + 5-5 + 4 + ? + ? = 44-5 mm. The joint between the third and 

 the ungual phalanx is hidden, but these two together measure 1 9 mm. 

 Of these bones the second metacarpal is the largest, and at its basal 

 end it is under 4 mm; thick. 



Some of the bones corresponding to these are to be seen in the 

 London specimen : but as they are displaced, it is not possible to 

 identify them with certainty. What Owen called the two terminal 

 phalanges of the digit I, closely resemble the two terminal phalanges 

 of digit II of the Berlin specimen, and I take them for these phalanges. 

 They measure respectively 22 mm. and 15 mm., i.e., they exceed the 

 bones of the Berlin specimen in the proportion of rather over 9 to 8. 

 To justify this determination I give the lengths of some other bones 

 in the specimens. The first number in each case is the length of the 

 bone in the Berlin specimen ; the second, that in the London speci- 

 men. Ulna, 56 mm., 63'5 mm. ; Radins, 55 mm., 62 mm. ; Femur, 

 51 mm., 58 mm. (1) ; Tibia, 71 mm., 81 mm. In each case except 

 that of the femur the ratio is almost exactly 8 : 9, and in the case of 

 the femur it is impossible to measure the exact length in the Berlin 

 specimen. The numbers of vertebrae in the tails differ in the two 

 specimens, so that it will not be safe to take the ratio in length of the 

 two tails as a guide. There is no other bone which can be identified 

 and measured with certainty in both specimens, so we may adopt 

 8 : 9 as the relative sizes of the Berlin and the London specimens 

 respectively. 



But in thickness a different relation holds. In corresponding 

 bones of two similar animals we find that the ratio of thickness 

 to length is always greater in the larger animal. And this is 

 true here : all bones of the London specimen are stouter and more 

 massive than those of the Berlin specimen. Now, in the London 

 specimen two conspicuous bones were identified by Owen as the 

 "third" and "fourth" metacarpals. They measure 39 and 33*5 mm. 

 respectively in length. In thickness they are much greater than any 

 hand-bone of the Berlin specimen. Others have regarded these bones 

 as the second and third metacarpals. Suppose this were the case, 

 then we get these ratios between the London and Berlin specimens. 



