356 BIRDS. 



upon which they feed ; they may sometimes be seen skimming over lakes and 

 rivers in the interior of the country. 



The Skimmers (Rynchops) resemble the sea-swallows in the smallness 

 of their feet, their long wings, and their forked tail, but are distinguished from 

 all other birds by the extraordinary structure of their beak the upper man- 

 dible is much shorter than the lower, and both so flattened sideways that they 

 resemble scissor blades, the edges of which meet without fitting into each other. 

 These birds, therefore, only obtain their food by skimming the surface of the 

 water as they fly, by means of their projecting lower jaw. 



IMG. 394. CORMORANT. 



TRIBE III. TOTIPALMAT/E. 



The birds belonging to the tribe Totipalmatae * are recog- 

 nizable from the circumstance that all the four toes, including the 

 hind one, are webbed together by a membrane, thus constituting 

 them the most perfectly constructed for swimming of the whole 

 race ; and yet, notwithstanding this, they are the only Palmipedes 

 that perch on trees. Their legs are short, and they are all excel- 

 lent swimmers. To this tribe belong 



The Pelicans (PeKcamda\ comprehending those genera which have a 

 space at the base of their beak denuded of feathers. Their nostrils are slits, 



* Totus, entire; palma, the sole of the foot: so called because their toes are united 

 together by one continuous web. 



