VERTEBRATA: AVES. 603 



still short as compared with the size of the body, and are of 

 more use as fins than for flight. The Great Auk or Gare-fowl 

 ( Aka impennis) is remarkable for being one of the birds which 

 appear to have become entirely extinct within the human 

 period, having been, in fact, destroyed by man himself. It 

 abounded at one time on both the American and European 

 sides of the North Atlantic, and used to visit the shores of 

 Scotland in summer for the purpose of breeding. The Little 

 Auk (Mergulus alle) occurs still in abundance in the seas of 

 northern regions. Other well-known members of this group 

 are the Razor-bill, the Puffins (Fratercula arctica], and the 

 Guillemots ( Urid). The Guillemots have a short tail, narrow 

 and pointed wings, short feet, and no hallux. Like the other 

 members of the family they inhabit northern and polar regions. 



In the Divers {ColymbidcK}^ comprising the true Divers and 

 the Grebes, the power of flight is pretty well developed, but 

 the bird still is much more active in the water, swimming or 

 diving, than on land. The Grebes are not uncommon in 

 Britain, and are largely killed for making muffs, collars, and 

 other articles of winter dress. They have the membrane 

 between the toes deeply incised. They haunt the sea as well 

 as lakes and rivers, and swim and dive admirably. In the 

 Divers proper the front toes are completely united by a mem- 

 brane. The Northern Diver or Loon (Colymbus glacialis) is 

 a familiar example, and is found on the coasts of high northern 

 latitudes. 



Fam. 2. Longipennatce. This family of Natatores is charac- 

 terised by the well-developed wings, the pointed, sometimes 

 knife-like, sometimes hooked bill, and by never having the 

 hallux united with the anterior toes by a membrane. The 

 following are the more important groups coming under this 

 head : 



a. Laridce, or Gulls and Terns, having powerful wings, a free 

 hinder toe, and the three anterior toes united by a membrane. 

 The Gulls form an exceedingly large and widely distributed 

 group of birds ; and the Terns or Sea-swallows are equally 

 beautiful, if not quite so common. The Terns are distin- 

 guished by their long and pointed wings, forked tail, and 

 comparatively -'short legs. They fly with great rapidity over 

 the surface of the sea, from which they pick up their food. 



b. Procellaridce, or Petrels, closely resembling the true Gulls, 

 but having a rudimentary hinder toe, and having the upper 

 mandible strongly hooked. The smaller species of Petrel are 

 well known to all sailors under the name of Storm-birds and 

 Mother Carey's Chickens. They are nocturnal or crepuscular 



