STRUCTURE AND HABITS OF ARCIIiEOPTERYX. 271 



at the distal end of the right radius and ulna. Tt is for a carpal bone, 

 of enormous size, and I am not prepared to believe that it played no 

 part in the support of the metacarpals. 



Of the distal row of carpals it is only possible to say that they are 

 not recognised in either specimen. Whether they have fused with the 

 metacarpals, as they do in modern birds, or were cartilaginous and so 

 not preserved, or were fused with the bones I have referred to as 

 belonging to the proximal row; or whether the two figured by Owen 

 and Dames are the proximal row, and the large bone I have called 

 "ulnare" is really, as the London specimen suggests, a fused mass 

 representing the whole or part of the distal row of carpals, can only be 

 decided, so far as I can see, by one of two consummations "devoutly 

 to be wished" — (1) the excavation of the exceedingly thin and fragile 

 Berlin slab from the back, or (2) the discovery of fresh specimens. 

 The first of these involves too great a risk to what it is hardly an 

 exaggeration to say is the most valuable palaeontological specimen in 

 any museum in the world. 



To admit that one does not know what that bone is, is one thing ; 

 to ignore its existence is another. Whether it be right or wrong, I 

 shall for the present call it the ulnare. Subsequent proof that it is 

 something else, e.g., a crocodilian "lenticulare," or, as seems not 

 improbable, unciforme, will not invalidate my argument. 



The hand has been much misrepresented both in words and in 

 drawings. There are five digits and no fewer, and I never suspected 

 that it would be necessary for me to give further proof than that 

 already given in my essay on errors. This conclusion, however, having 

 been controverted, I will venture now to prove it over again by three 

 distinct proofs, each of which is in itself conclusive. 



(1.) Three long, slender fingers on each hand are plainly seen on the 

 Berlin slab. They are made up of two, three, and four phalanges 

 respectively, in addition to a metacarpal each. Each bears a claw, 

 which, though not easily made out in the photographs, especially in 

 the smaller photographs, is perfectly distinct in most cases in the slab 

 itself. There can be no doubt, and nobody does doubt, that these 

 three correspond to the digits I, II, and III respectively of the normal 

 pentadactyle reptilian fore-limb. The lengths of the various meta- 

 carpals and phalanges in the Berlin specimen are as follows, beginning 

 at the proximal end, i.e., with the metacarpal, in each case : — 



