24 The Ottawa Naturalist. [May- 



Regarding the fore feet as webbed and adapted for swim- 

 ming, the digits were most probably capable of being spread 

 laterally to some extent, probably more than is indicated in 

 the figure forming plate II, which is intended to represent the 

 hand in a moderately quiescent state. 



As shewn in plates I and III, the metacarpals II, III and 

 IV of both hands are parallel to each other and pressed together, 

 with metacarpals II and IV brought round metacarpal III 

 toward each other; the result probably of the contraction of the 

 skin after the death of the animal and not indicative of the proper 

 position of these bones when the creature was alive. Mr. Brown, 

 in figure 1 of his paper, already cited, representing the " Manus 

 of Trachodon correctly assembled" places metacarpals II, III 

 and IV in this position of close contact which is not, in the 

 writer's opinion, the true position of these bones in a fore foot 

 capable of being used with much effect in swimming. 



In the Red Deer river specimen the different bones of the 

 digits are distinctive in shape and can be recognized in each 

 hand. Metacarpals III and IV are of about equal length. 

 Metacarpal II is considerably shorter, and metacarpal V is less 

 than half as long as Nos. lit and IV. The distal end of meta- 

 carpal III is enlarged, but in the other metacarpals the proximal 

 end is the larger, the difference in size between the two ends 

 being not so great in metacarpal II. The articulating surfaces 

 of these bones are evenly rounded. 



Plates I and III shew accurately the relative position of the 

 bones of the hands to each other as found. 



Digit V has two phalanges, of which the terminal one is 

 smaller than that of digits III and IV. It has a more rounded 

 outline, but, as in the others, is thick proximallv and thin toward 

 the distal margin. This terminal bone is well preserved in the 

 right hand, is in position, and is in all respects a typically shaped 

 hoof-bone. In the left hand a fragment regarded as the proximal 

 end of the corresponding bone of digit V is shewn slightly in 

 advance of the first phalanx. 



The hoof-bone of digit IV of the right hand was found 

 slightly out of place, as indicated in plates I and III. The 

 corresponding bone in the left hand was missing and has been 

 restored in plaster. 



The three phalanges of digit III of the left hand are pre- 

 served and were found practically in place as shewn. The second 

 phalanx of digit III of the right hand was missing and has been 

 restored from the left hand, the restoration being placed in the 

 sacpe found between the first and third phalanges. 



