1906.] SYSTEM OF CERTAIN SPECIES OF AXURA. 1009 



of the same species, considerably lessens the importance attaching 

 to such variations as may occur between isolated iiadividnals of 

 different species. Dealing with limited m.aterial, the present 

 paper is submitted in the hope that it may not be without value 

 as a contribution to the further study of the subject, and more 

 especially perhaps from the wider aspect of the arterial system of 

 the Anui-a as a whole. 



In the portion of the arterial system here considered, the 

 Act. carotis cerebraUs, OGcijjito-vertebralis, bracMalis, and ischia- 

 dica are omitted. The species will be considered together as far 

 as possible, the account in Gaupp's edition of Ecker's and 

 Wiedersheim's ' Anatomie des Frosches ' being followed as a basK 

 of I'eference. The nomenclature of the arteries is that adopted 

 in the same work, but in the case of the muscles the system used 

 in the original edition of Ecker is retained. In i-egai-d to the 

 latter, among the muscles to be referred to a diffei-ence of nomen- 

 clature occurs in the following: — 



Ecker. Gaupp. 



J/, coraco-hicmeralis. = JI. coraco-brachialis longus. 



„ ileo-psoas. = ,, iliacus internus. 



,, infraspinatus. — „ dcrsalis scapula;. 



„ levator angidi scapidce. = ,, levator scapidce inferior. 



,, obliquus internus. = „ transversus. 



,, sicbscapidaris . = „ coraco-brachialis breris. 



,, transverso-sca2ndarismajor.= ,, serratus inferior. 

 ,, ,, ,, minor. = ,, ,, medius. 



„ triceps brachii. = ,, anconeus. 



The A. hidbi -cordis had not in all cases the same point of 

 origin. In R. tigrina, R. clamata, and R. catesbiana, it ai'ose 

 fi-om the base of the right carotid arch ; in R. hexadactyla. the 

 same, but close against the margin of the right systemic ; in Bufo 

 boreas from the base of the right systemic ; in Bifo mauritanicus 

 from the base of the left carotid arch. In each case, the artery 

 ran across the base of the three right arches and divided into 

 branches supplying the dorsal and ventral sides of the bulbus 

 liut not apparently extending beyond it. 



I. Carotid System. 



The A. carotis externa appeared in Bufo boreas to arise from 

 near the centre of the carotid gland, instead of from its 

 proximal mai-gin as in other species. 



The r. mibsculo- glandularis was given off' a, short Avay from 

 the base of this artery in all the species, supplying vessels to the 

 thyroid gland and hyoidean muscles in this region. The close 

 association of this branch with the thyroid w^as especially 

 well exhibited in R. hexadactyla and R. tigrina, where the gland 

 was much bi'oken, and a branch of the artery ran in communi- 

 cation with the several disconnected portions. It is remarkable. 



