CLASS AMPHIBIA 



505 



each side of the body, the anterior carotid arch, the middle, systemic 

 arch, and the posterior, pulmo cutaneous arch. 



The Carotid Arch. — Each carotid arch divides into two branches. 

 The more ventral, Ungual artery, or external carotid, passes forward, 

 giving branches to the thyroid, pseudothyroid, muscles of the hyoid 



External c 



Auricularis 



i 



ral 

 Occipital 

 Internal carotid 



Cutaneous 

 Carotid qiand 



Conus arteriosus- 

 Pulmonary. 



Systsmic arch 



Lateralis 

 Dorsalis 



Cozliaco.rnesenteric 



Brachial 

 Vertc bra I 



\^Left qastric 



PANCREAS 



].Riijht Cjastric 

 l_Coeliac 

 Anterior 

 mesenteric 



Splenic 



(Irinoaenital 



Epigastric 

 Viae 



Recto.vesical 

 Sciatic 



■■RECTUM! pogfer/or mescnter/c 

 , -'h^^^^^emora I 

 i h 



Fig. 275. — Arteries of the bullfrog from ventral view. (Drawn by Ruth M. 



Sanders.) 



and tongue, and then extends along the edges of the lower jaw. 

 The internal branch is larger and is called the internal carotid. It 

 has at its base a spongy enlargement known as the carotid gland 

 which by its structure serves to steady the pressure of blood passing 

 into the artery. This artery follows the side of the neck to the base 



