COMMON FROG. 271 



ration of the two organs. The conus bifurcates into the two great 

 divisions of the truncus aortae, which are each subdivided by internal 

 partitions into three canals. These canals become three tubes, the 

 carotico-lingual, the aortic, and the pulmonary trunks, of which the 

 first is most internal and anterior, and the last the most external and 

 posterior. 



q'. Conus arteriosus, with the auricles one on each side. It inclines to the 

 left, and is attached on that side to the ventricle by the frenulum bulbi 

 of Briicke. Denkschrift Akad. Wienj Bd. iii. 1853, p. 355. 



r. Lingual branch of the first of three trunks arising just internally to a 

 rete mirabile known as the ' carotid gland,' from the outer side of 

 which the carotid artery, called sometimes the ' ascending pharyngeal,' 

 passes to the back of the oesophagus in close apposition with the 

 second main trunk or aorta. 



s. Convergence of hyoglossi muscles. 



/. Geniohyoid muscle. 



ii. Left external jugular vein passing down to unite with a vein formed by 

 the union of the cutaneous vein with the vena anonyma, and thereby 

 constitute the vena cava superior of the same side. 



