456 Vertebrata. 



fowl (Nwmida meleagris), with naked head, which bears a large bony process; 

 grey, with white spots; without spur : indigenous to Africa. 



3. The Ourassows (Craeidx: genus Crax, etc.). Large, with fah-ly 

 long metatarsus, curved and pointed claws; long tail; beak covered at the 

 base with soft naked skin (cere), where there is often a large knob; an 

 upright crest of feathers, frequently curves forwards from the top of the 

 head : breed in trees : Mexico and South America. 



4. Mound-birds or Talegallas (genus Megapodius, etc.), dis- 

 tinguished by the length of the claws and the powerful structure of the hind 

 toe, which is articulated at the level of the other toes. They are specially 

 remarkable in that they do not brood over their very large eggs, but deposit 

 them in a mound of vegetable matter, which they have collected, in a sand 

 heap, or in a pit dug in the sand; the eggs are then either incubated by the 

 warmth resulting from the fermentation of the vegetable matter, or simply by 

 the heat of the sun. The young ones lose the covering of down whilst still within 

 the egg, and hatch out with the adult plumage. Aiistralia, the Philippines. 



Order 5.. Natatores {Swimming Birds). 



The feet are generally pedes palmati, i.e., a laembrane is 

 stretched between the front toes almost to their tips. As a rule 

 the feet are short, the claws short and flattened, the hind toe 

 generally very small, the lower end of the fore leg bare and 

 scaly. The tail is usually short ; the plumage thick and elastic. 

 The Natatores are able to swim by means of their hind limbs, and 

 not a few of them can dive, when they often use the wings as 

 swimming organs • others can only bring the head, neck, and fore 

 limbs below the water, the rest of the body remaining above. Usually 

 they cannot walk well ; the power of flight is considerable in some 

 forms, in others it may be lost. 



1. The G-ulls (Longipennes). Long, pointed wings ; short hind toe ; lateral 

 slit-like nares ; tail well-developed. Most are coast-birds (some may also live near 

 fresh water), feeding on Pisces and other marine animals, for which they plunge 

 into the sea ; excellent fliers. The Gulls (Larus) are large and light-coloured, 

 with the tip of the beak curved ; and a stumpy tail ; numerous species on the coast 

 of Great Britain : the Common Gull (i. caraMs), the Black-headed Gull 

 (i. ridibwndws), the Laughing Gull {L. atricilla), the Herring Gull 

 [L. argentus), and others. The Terns {Sterna) differ from the Gulls in their 

 long, straight, pointed beaks, and their forked tails. Out of eight or nine species 

 occurring on English coasts, the Common Tern (S. hirundo), and the 

 Lesser Tern (S. mmwia), may be noted. An interesting form is Buffon's 

 Skua (Lestris), dark in colour, with the two median rectrices longer than the 

 others, and the beak grooved. The Skuas follow other marine forms which have 

 secured any prey, seizing upon it if the possessors allow it to fall ; they also fish 

 for themselves, and behave as true Birds of Prey, since they hunt small Birds 

 and Mammals. They are northern, and ai-e met with in the Orkneys. 



2. The Petrels {Tubinares). Chiefly distinguished from the preceding 

 gi'oups, in that the nares are situated at the ends of two tubes lying above the 

 beak ; usually met with in the open sea. Among those on British coasts, may 

 be noted, the Fulmar Petrel {Fwlmarws glacialis) of the Orkneys' and 

 St. Kilda's, and the small, dark-coloured Stormy Petrel (Procellaria 



