256 



ROY L. MOODIE. 



were not developed so that clasping organs may safely be ascribed 

 to species of the other three genera. There is no reason why 

 the limbed forms might not also have possessed the clasping 

 organs. 



Among the recent Amphibia, so far as I am aware, there are 

 no bony or cartilaginous elements in the abdominal wall. Both 

 the chevron armature of the extinct forms and the well developed 

 " Kammplatten " are absent among the modern Amphibia. The 

 recent forms do, however, have well developed clasping organs, 

 at least in some cases. It will be of interest, in this connection, 

 to examine the condition of the clasping organs in the recent 

 forms as a comparison to those found in the extinct species. 



Among the Salientia the clasping organs 

 are usually developed on the fore limbs and 

 consist for the large part of wart-like or 

 spine-like excresences on the skin. These 

 asperities are developed on the inner side 

 of the fore legs and on the breast of the 

 males. " Nuptial excrescences on the inner 

 metacarpal tubercle and on the inner fingers 

 of the male are common ; they reach their 

 greatest development in the Himalayan 

 Rana liebigi, the male of which is ' remark- 

 able for the extreme thickness of its arms, 

 the inner sides of which are studded with 

 small conical black spines, each supported 

 on a rounded base produced by a swelling 

 of the skin. A large patch of similar 

 spines exists on each side of the breast.' " * 

 In the genus Leptodactylns, from Central 

 and South America, a specimen of which 

 I have studied in the Field Museum, the 

 first digit is somewhat swollen to support two black, horny spines 

 (Fig. 5), which project on the inner side of the finger. There 

 are many variations of these two extreme cases cited above but 

 in all they are on the same general plan. In most cases the 

 clasping organs are only developed during the breeding season. 



1 Boulenger, "Cat. Batrach. Salientia," p. 22. Gadow, 1901, " Amphibia and 

 Reptiles," p. 250. 



Fig. 5. The right 

 hand of Leptodactylns. 

 From a specimen in the 

 Field Museum. En- 

 larged. 



