Ruth, E. S. : Reconstruction of Duck Twins.] 



[Phil. Journ. Sci., XIII, B, No. 4. 



omv 



am v 



v e h 



m v 



va 



0)71 v 



m, v 



Fig. 1. Dorsal view of pharynx and aortae. 

 Duck twins III. 



Fig. 2. Ventral view of pharynx, tubular heart, 

 and aortae. Duck twins III. 



Ida 



om v 



mda 



Fig. 3. Ventral view of pharynx and aorta. Fig. 4. Dorsal view of pharynx and aortae. 



Duck twins V. Duck twins V. 



PLATE II. 



