of the Hand in Pipa ant? Xenopus. 201 



that the bone which carries metacarpale V is carpale 5, 

 because they have found in a single species {Xenophrys) a 

 small cartilage (said even to ossify in old specimens) in the 

 ligament which extends from carpale 4 to metacarpale V, 

 also seen in Bomhinator and Discoglossus, which carti- 

 lage (or ligament) they regard as the true carpale 5, while 

 they interpret the latter bone as an ulnar centrale ; thus the 

 hand would possess two centralia, both dislocated towards their 

 respective sides of the hand. In a Boml>inator-\avva having 

 the fore limbs yet included in the gill-cavity, but the outer 

 side of the forearm and the two outer fingers coloured, I have 

 not found any trace of this ligament, and it seems to me 

 very improbable that two centralia should be greatly 

 developed and still both lie out of their primitive position. 

 On the whole, I am unable to admit that tlie later investiga- 

 tions have made it necessary to give up the interpretation 

 due to Gegenbaur ; therefore I have followed him, and I 

 have named the carpal bones in Xenopus [cf. figs. 5, 6, p. 205) 

 in accordance with his views. Now, in comparing Pipa 

 with the latter, the reductions met with in Pipa will be easily 

 exj)lained. It is thus quite certain that the great ulnar bone in 

 Pipja consists of the coalesced ulnare and carpale 5, for m Xeno- 

 pus we recognize the process x on the ulnare, and the process y 

 on carpale 5 ; besides, the above-mentioned artery, which in 

 Xenopus is seen at a, runs in Pipa in a groove under a pro- 

 jection of the great ulnar carpale, carrying the articular face 

 for the radius, and mesially to this artery we find the two 

 articular faces where the pieces r and C-fC2 join, but in 

 Xenopus r and C articulate with Cg. Hence it follows that 

 r in both genera is the same bone, radiale. The bone in 

 Pipa which carries metacarpale 11 is in all probability 

 the coalesced centrale and carpale 2 ; closer examination will 

 show a trace of a process answering to the large process on 

 C in XenojmSy and this being the case the bone in question 

 contains at any rate the centrale, and I see no reason why the 

 carpale 2 should have quite disappeared. 



Howes and E,idewood have also interpreted the just- 

 mentioned bones in a similar manner; whereas Brlihl, witliotit 

 further ceremony, designates the bone C -t- Co as the carpale 2, 

 making no remarks as to the absence of our centrale (Endo- 

 diacarpale or Endo-radiocarpale of Briihl). 



Tlie metacarpals in Pipa do not seem to have attracted 

 the special attention of previous authors, probably because 

 their form apparently corresponds very well witli the sup- 

 posed volar lace, but undoubtedly the mistakes are mainly 

 due to the singular form of these bones. Metacarpale Jl is 



