58 TOTIPALMATE SWIMMERS. 



32 WHITE BELLIED PETREL. 



8.50. Tail emarginate. Black or dusky 

 above and on throat. Belly and under tail 

 coverts white. Intertropical seas, north oc- 

 casionally to the coast of Florida. 



33. WHITE-FACED PETKEL. 



About the size of the White-bellied Pe- 

 trel. Dark above with the upper tail cov- 

 erts ashy. Forhead, line over eye, and low- 

 er parts white. Southern Seas, accidental 

 off the coast of Massachusetts. 



TOTIPALMATE SWIMMERS. 



This is a group of easily recognized 

 birds. They are of somewhat varying size 

 but none are very small, while others are 

 quite large. 



The external characters possessed in 

 common, and which bind the group togeth- 

 er, are, hind toe connected to the anterior 

 toes by a web, fig. 39, and a more or less well 



