464 Vi-rtebrata. 



tuimelB, 1 m. to 1'5 m. long in perpendicular walls of sand; and breed in the 

 innermost, somewhat widened portion. 



5. The Common Creeper (Certhia familiaris), the Nuthatch 

 (Sitta exsia), and the Wall Creeper (Tichodroma mvraria) belong to a 

 special group of the Osoines, and are characterised by the very great size of the 

 hind toe, whilst the fore toes are enclosed at their roots in a common skin. The 

 claws are much compressed and very pointed. They are all found in England, but 

 the Wall Creepers are very rare. They run up the trunks of trees or up rocks. 

 All the Creepers have long, thin, arched beaks (longest in the Wall Creepers) ; 

 the Nuthatch has a straight, strong, pointed beak. The Wall Creepers are Alpine. 



6. Larks {Alaudidx), distinguished from all the other Oscines so far 

 mentioned in that the metatarsus is covered posteriorly by several small 

 plates. The hind toe has a long, straight claw; the beak is of medium 

 length, fairly strong and almost straight, the summit arched. They feed chiefly 

 on seeds, and nest on the ground ; the following occur in England : the Sky 

 Lark (Alavda arvensii), iAiei Wood Lark [A. a/rborea), and the Crested 

 Lark (A. eristata), the last is rare. The Shore Lark (Otocoris alpestris) 

 is of striking appearance, it inhabits the Northern parts of Asia and Europe, 

 and not infrequently visits the East coast of Britain. Allied to the Larks is the 

 Hoopoe (Upupa epops), with long, thin, arched beak, a hind claw like theirs, 

 and an upright tuft of feathers on the head. Rather rare in England. 

 Insectivorous, migratory. 



7. The Lyre Birds {Menura), fowl-like, with short, straight beak. 

 They are characterised especially by the peculiar, long, lyre-shaped tail of the 

 males. The innermost and the outermost rectrices are curved outwards, the rest 

 are thinly furnished with long barbs, which possess no barbules : Australia. 



Order 9. Clamatores {Shrieking birds). 



Distinguislied from tte Singing Birds in that the hind toe, and 

 especially its claw, is less powerful and that it cannot be moved by 

 itself. The singing muscles are not developed. 



1. The Roller {Coracias garrula). Beak of medium length, compressed 

 in front, broad at the base, slightly arched at the tip. Gorgeous blue-green; 

 about the size of a Thrush ; comparatively rare in England ; nests in holes in 

 trees ; insectivorous and migratory. 



2. Swifts (Cypselidse). The mouth very large, extending back behind the 

 eye ; beak short and weak ; broad at the base and flattened ; uncommonly long 

 wings, very small feet. Insectivorous forms like Swallows. In England occurs 

 the Common Swift {Cypselus opus), in which all four toes are directed 

 forwards ; the dish-like nest is foi-med in holes in walls, etc., and is built of 

 straws and feathers, which are bound together by saUva. The Swifts are repre- 

 sented in the Alps and on Mediterranean coasts by the very similar, somewhat 

 larger, Alpine Swift (C^/^seZtts meZfeo), with white abdomen ; it occasionally 

 visits England. The Salanganes (CollocaUa), with normal feet, but in 

 other respects like the foregoing species, live in the East Indies, and construct 

 their nests of saliva (edible birds-nests). To an allied family belongs the 

 Nightjar {Caprirmdgus ewropxus), -which, is large, brown, and coloured Hke 

 an Owl; feather bristles at the base of the beak; nocturnal; the eggs are laid 

 on the bare ground. A summer visitant to Britain. 



3. Humming Birds {Trochilidx). The beak is long, thin, and tubular ; 

 the tongue is deeply cleft and can be greatly protruded. The wings are long ; 



