Aiiatoiay of Hyla aurea. 



351 



vessel to the laiynx, as it had been cut previously tu coming 

 into my possession. There was in this animal no vessel to be 

 found correspondinsf to that gointr to the skin from the extra 

 arch in the other individual. In C (Text figure .3) the extra arch 

 on the R. side does not open into the cutanecms artery at all, 

 but gives off a large and long branch, accompanying it to its 

 destination. The rest of this arch curls inwards to open into 

 the systemic arch after giving off branches to the siu'rounding 

 muscles. 



It is quite evident that this extra arch corresponds to the 

 3rd branchial aroh of the embryo which normally dis.appears in 

 the frog, but has in these case® been retained. 



In a fourth individual (Text figure 4) there were onl}- the 



Individual of Hyla aurea, showing abnormal Carotid and Systemic 



ircbes. 



1. Carotid arch. 



2. Systemic arch. 



4. Puhno-cutaneous arch, 



o. Occipital artery. 



s. Subclavian artery, 



e. Oesophageal arteries. 



d.a. Dorsal aorta. 



c.-m. Coeliaco-mesenteric artery. 



