1022 



MR. L. R. CRAAVSHAY ON THE ARTERIAL [Dec. 11, 



of tlie more primitive condition were more or less retained. In a 

 specimen of B. temporaria each side received ten arteries, three of 

 which ai'ose independently from the aorta. In £. vxauritanicus 

 there were four vessels, three of which divided into right and 

 left branches, the fourth going to the right kidney alone. In 

 B. clamata, five vessels went to one side and four to the other. 

 Of these nine vessels, five had independent origins (text-fig. 152, 

 p. 1027). In B. tigrina on each side there were eight arteries, 

 three of which weie distinct in origin. In B. catesbicma there 

 were six arteries to each side, four of them arising quite inde- 

 pendently from the aorta, so that here there wei'e only two which 

 bifurcated right and left (text-fig. 148). 



Text-fiff. 148. 



o.f.l.'-- 



Sana cateshiana, ^ (X 1). 



Ventral view of Aa. nrogenitales, &c. 



(For explanation of the lettering, see p. 1033.) 



With a doubtful exception and one clear case in a specimen 

 of B. temporaria, the A a. genitales did not arise, in any of the 

 individuals examined, independently from the aorta, but always 

 in common with a renal vessel. Generally they separated from the 

 renal vessel a considerable distance from the aorta, but sometimes 



