462 CARPUS OF HTMENOCHIRTJS BOETTGERI. 



or ulnare, confluent with the post-axial centrale, as in Pipa. The 

 distal carpal of the fifth digit is probably absent and not included 

 in tliis bone. The fourth carpal is free. Seen from above, it 

 articulates with a part of the third metacarpal as well as the 

 fourth, but an examination of the palmar surface of the carpus 

 suffices to show that this element belongs exclusively to the 

 fourth digit. 



In Pipa the third carpal is free, while that of the second digit 

 is (presumably) fused with the naviculare or pre-axial centrale, 

 but there is no distinct carpal to either the second or third digit 

 in Hymenochirus. Whether the carpals of these digits have 

 dwindled away and left no traces, or whether they have fused 

 with the naviculare, it is impossible to say. Tlie appearances 

 rather suggest that the latter is the more correct interpretation. 



The lunatum (Z) is normal, and calls for no comment. 



The pollex is represented by a single lenticular bone, probably 

 carpale 1, which lies on the ventral surface of the naviculare. It 

 is concealed by the latter in a dorsal view, but its position is, 

 indicated in the figure by a dotted line {po. 1). 



The terminology used in this note is the same as that employed 

 by Prof. Howes and myself in 1888. The arguments propounded 

 by Perrin, Emery, and Zwick do not appear to be of sufiicient 

 weight to warrant the relinquishing of the opinions we then 

 held as to the morphological value of the parts of the Anuran 

 manus. 



EXPLANATION op Fig. 5, Plate 31. 



Carpal skeleton of Hymenochirus Boettgeri, dorsal view ( X 12). 



I. Lunatum. 

 n. 2, 3. Naviculare confluent with the carpals of the second and third 

 digits. 

 pk. Pyramidale confluent with the post-axial centrale, 

 po. 1. Carpal of the pollex. 

 r. Radius, 

 s. Radial sesamoid. 

 u. Ulna. 



4, Carpal of the fourth digit. 

 2', 3', 4', 5'. Metacarpals of the second, third, fourth, and fifth digits.- 



