1908.] BATRACHIAN RHINODEKMA DARWINI. 681 



this section of the gut and that which precedes is rather in the 

 abrupt thinning of the lining membrane than in anything else. 

 Later on the reticulate arrangement is still retained ; but there 

 is a tendency towards emphasising the transversely running folds 

 of the reticulum, but to nothing like the extent that is figured in 

 Bana*. These facts are well shown in the accompanying figure 

 (text-fig. 143). The small intestine opens very abruptly into the 

 short dilated colo-rectum. A little way in front of the junction 

 of the two the ileum, as we may term it, becomes somewhat 

 narrower in calibre and it has been for some distance thicker- 

 walled. The end of the small intestine in fact is as thick-walled 

 as that part of the tube (whatever its homologies may be) which 

 immediately succeeds the dilated stomachal chamber. Both these 

 regions contrast very markedly with the thin-walled middle 

 section of the gut. On cutting open, these difierences were very 

 apparent. The colo-rectum is also thin-walled — at any rate in 

 comparison with its calibre. The end of the ileum actually 

 projects into it for some distance, like the uterus into the vagina. 

 The figure which I give here of the intestinal tract of Ehinoderma 

 (text-fig. 143) may be compared with that of Breviceps'f, although 

 the former is represented as seen when cut open and the latter is 

 not. I have pointed out in Breviceps % that the stomach does not 

 end where it suddenly diminishes in calibre, but that it is clearly 

 continued for a short distance along the upward limb of the li 

 which it forms with the duodenum. I believe that in Rhinoderma 

 this extension of the stomach is still greater. 



Text-fig. 144. 



Alimentary tract of Rhinoderma darivini, to illustrate the shortness of that of the 

 male (upper figure) and the greater length of that of the female (lower figure). 



The accompanying drawings (text-fig. 144) show the different 

 appearance of the gut in the male and in the female of this frog. 



* Haslam, loc. cit. p. 288, fig. 189. 



t P. Z. S. 1908, p. 32, text-tig. 10. I Loc. cit. p. 31, text-fig. 9. 



