o/ the Hand in Pipa and Xenopus . 203 



doigt est le plus long des quatre, aprcs lui c'est Ic troisifeine, 

 ensuite le premier, puis le dernier, qui est par consdquent le 

 plus court." Thus here also we meet with the common 

 mistake. 



Of tlie old authors Bonnet * perhaps observed the correct 

 numbering of the fingers ; he says '^ . . . leur longueur dtoit 

 indgale. Le troisieme qui etoit le plus long ....;" but 

 whether he really had a clear idea of the hand cannot be 

 decided either from his text or figures. 



If we now make an examination of the exterior of the 



hand we shall observe the following facts : the back of the 



hand is concave, the palm convex, and the outer fingers can 



be turned inwards over the middle ones, so that the hand 



acquires the peculiar narrow form which is often seen in 



specimens preserved in spirit and which certainly will be 



found in the living animal. The distribution of colour that 



in Anurans usually very distinctly characterizes the lower and 



upper sides is here but feebly marked ; yet I have found 



among the specimens which I had the opportunity of examining 



a few in which the colour was paler and spotted, like the belly, 



on the inner side of the arm as well as on the upper side of 



the wrist and the three inner metacarpals ; besides, the skin 



on the back of the hand is often somewhat smoother and finer 



than on the palm. That a hand like this is used very little 



for walking seems evident ; the absence of tubercles from the 



palm points in the same direction. Unfortunately we know 



nothing as to the mode of locomotion in the genus Pipa, our 



information concerning the habits of this animal being very 



scanty; the old and hitherto (as far as I knov/) tlie only 



observers of the animal in the living state (Miss Merian and 



Dr. Fermin) merely noticed its singular mode of breeding. 



Probably Pii^a will be found essentially aquatic in its habits. 



Miss Merian t only says that it dwells on a plant growing in 



the water. Fermin % states that it lives in the swamps of 



the thick forests, and that the specimens he kept were 



almost constantly swimming about, and scarcely ever sat 



quietly at the bottom. 



* " Observations sur le Pipa ou Crapaud de Suriuam," Joiu'nal de 

 I'bysique, t. xiv. 1770, p. 427. 



t ' IJe generatione et metamorphosibus iusectorum Surinamensium,' 

 AiHstelod., 1710, p. 70. 



f ' Abbaudluiioen von der Siu'iuamischen Kriite &c.,' ub^rsetzt v. Goeze. 

 ikiuiuscbweig, 177 (J. 



