62 



ZOOTOMY. 



^ 



Fig. 20. — Raja nasuta. Tlie arterial system, seen from the ventral 

 aspect (one-third nat. size). 



The heart and ventral aorta (v.ao) are slightly displaced towards the 

 right side (left in the figure) : the left afferent branchial arteries {a.br) 

 are removed, and the right efferent branchials (e.br) : the lelt efferent 

 branchials are straightened out, so as to bring their ventral ends to the 



