PLATE XII 



EXPLANATION OF FIGURE 



17 Adult eat (from Metcalf, fig. 1, '18), Type ACD. Persistence of right 

 posterior cardinal, left supracardinal, and left posterior cardinal veins. Peri- 

 ureteric venous ring, through which ureter passes, present on left side. Legends 

 by. Metcalf. 



80 



