of the Hand in Pipa a«<^^ Xcnopus. 201 



that tlic bone wliicli carries nictacarpale V is carpalc 5, 

 because they liave found in a single species (Xenophri/.i) a 

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

 ligament which extends from carpale 4 to metaearpale V, 

 also seen in Bomhinator and Di.scoglossus^ which carti- 

 lage (or ligament) they regard as tlie true carpale 5, wliile 

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

 hand would ])0sscss two centralia, botli dislocated towards their 

 resj)ective sides of the hand. In a Boiubinator-lavva 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 tliat two centralia should be greatly 

 develo])ed and still both lie out of their primitive position. 

 On the whole, I am unable to admit that the 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 hitter, the reductions met with in Pipa will be easily 

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

 Pij)a consists of the coalesced ulnare and carpale 5, for m Xeno- 

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

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

 Xenopus is seen at a, runs in Pi2)a in a groove under a pro- 

 jection of the great ulnar carpale, carrying the articuhir face 

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

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

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

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

 Pipa which carries metaearpale 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 Xenopus, and this being the ease the bone in question 

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

 carpale 2 should have quite disappeared. 



Howes and Hide wood have also interpreted the just- 

 mentioned bones in a similar manner; whereas Briihl, wnthout 

 further ceremony, designates the boneC + Co as the carpale 2, 

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

 diacarpale or Endo-radioearpale of Briihl). 



Tiie metacarpals in Pipa do not seem to have attracted 

 the special attention of previous authors, probably because 

 their form apparently corresponds very well with the sup- 

 posed volar taee, but undoubtedly the mistakes are mainly 

 {\\\Q to the singular Ibrm of these bones. Metaearpale W is 



