19 



c, Webs between all toes (3 webs) 



Figure 6. 



Full-Wehhed Swimmers — Gannets, Cormorants, etc., p. 59. 



/' ^ 



Figure 7. 



Figure 8. 



Figure 9. Figure 10. 



d. Bill toothed or flattened (Duck-like). 

 Sieve-hilled Swimmers — Mergansers, Ducks, Geese, and Swans p. 62. 



e, Nostrils in tubes on top of bill. 



Tube-nosed Swimmers — Petrels, etc. 



Figure 11. 



p. 56 



