1908.] ANATOMY OP A FROG. 41 



(15) The coccyx is abbreviated and does not extend to the end 



of the body. To compensate for this the end section of 

 the cloaca which naturally extends beyond it is protected 

 by a pair of strong muscles which are inserted on to the 

 skin above the anus by short slips. 



(16) Upon each sacral transverse process is a detached plate 



of cartilage which is related to the adjacent musculature, 

 and which perhaps corresponds to the supra -sacral portion 

 of the ilium in Sauropsida. 



(17) The hyoid cartilage is marked by the double origin of the 



anterior cornua, a foramen therefore occupying the base 

 of each cornu where it joins the body of the hyoid. 



The above list contains a brief epitome of nearly all of the 

 points in which I have found Brevicejys to differ anatomically 

 from Rana. In the present state of our knowledge of Batrachian 

 anatomy, it is not possible to use them in order to criticise or 

 confirm any view which has been held with regard to the sys- 

 tematic position of Brevice2}s, except of course to assert that it 

 is in any case not a near ally of Banco, or of the family 

 Pelobatidae *. Some of its structural features would appear^to be 

 associated with its ant- eating proclivities; to this category I 

 would refer the particularly strongly-developed hyoid muscles and 

 the anterior cornua of the hyoid and the round, globular, some- 

 what gizzard-like stomach sharply marked off from both oesophagus 

 and duodenum. The burrowing habits of Breviceps are perhaps to 

 be associated with some other muscular peculiarities ; especially, 

 as I should imagine, the extent and muscularity of the two 

 obliqui and of their branches to the shoulder-girdle, and the very 

 powerful muscles of the anterior part of the thigh, and the 

 very thick gastrocnemius. Among the remaining characters of 

 this Frog, those which are particularly noteworthy appear to me 

 to be the following, viz. : — (1) The enormous size and muscularity 

 of the posterior lymph-hearts with their sjaecial extrinsic muscles ; 

 (2) the presence of a plate of cartilage overlying the sacral trans- 

 verse process and representing the supra-sacral portion of the 

 ilium in higher types ; (3) the nearly complete concealment of 

 the heart ventrally by the liver-lobes ; (4) the existence of only 

 one vas efferens for both testes. 



* Beddard, P. Z. S. 1907, p. 324, & p. 871. 



