1906.] 



SYSTEM OF CERTAIN SPECIES OF ANURA. 



1029 



variation in all but R. hexadacti/la, where the fii'st, which was not 

 observed, may however have been possibly overlooked. The 

 r. aioricularis in R. tigrina subdivided to supply the tympanic 

 memlirane and the Mm. depressor maxillce, infraspinatus , &c. In 

 R. clamata and R. catesbiana it supplied more especially the tym- 

 panic region ; in B. mauritanicus and J3. boreas almost entirely 

 so. In R. catesbiana^ as previously stated, this vessel formed, on 



Text-fii'-. 153. 



Bufo boreas, ? (XlJ). 



Portion of arterial system. Ventral view. 



Showing abnormality of A. pulmonalis on the right side of the body. 



s^-s^. Branches of A. subclavia. 

 s^ to M. levator angtdi soapulce. 

 s* to Mm. triceps hrachii, pcctoralis abdominalis, and subscapularis. 



(For other branches, see p. 1014. For explanation of other lettering, see p. 1033.) 



the right side of the body, a complete union near its origin with 

 a branch of the A. subclavia, presumably the thoracica superior. 

 On the left side of the body it ran independently to the tympanic 

 membrane, where it formed an anastomosis with a very small 



