THE ANNALS 



AND 



MAGAZINE OF NATURAL UISTORY, 



[SIXTH SERIES.] 

 No. 45. SEPTEMBER 1891, 



XXIII. — Bemarks on the Structure of the Hand in Pipa 

 and Xenopus. Bj Dr. Hector F. E. Jungersen, of 

 Copenhagen. 



In examining the hands of the two above-named Batrachians, 

 it will soon be obvious tliat the distinctly pronounced differ- 

 ence between the dorsal and volar sides met with in other 

 Anurans is here obliterated ; in both genera the tubercles 

 and warts usually characterizing the volar surface are 

 absent. This fact, together with the great similarity of 

 tlie fingers, renders it difficult to understand the liand cor- 

 rectly, as at first sight the inner fingers are undistinguish- 

 ab!e from the outer, and it is not clear which is the upper and 

 which the lower side. From the following it will appear that 

 hitherto all observers of Pipa and most observers of Xenopus 

 have been misled and have misinterpreted the hand in these 

 animals in one or both respects. 



As is well known, the hand in all Anurans has four 

 fingers (II-V), the two innermost of which (II and III) 

 in nearly all the Phaneroglossa are provided with two 

 phalanges, the two outer with three * ; also in Aglossa 



* Exceptions were first pointed out by Peters (Reise iiach Mossambiqiie, 

 iii. 1882), and lately Boulenger ("Note on the Classiticationof tlie llanidfe." 



Ann. ih May. N. Hist. Ser. 6. Vol. viii. 18 



