PALMIPEDES. 



253 



pointed nails. Thry are northorn binls, uhicli rarely nestle ^virh us. and visit these latitudes in 

 Minter, wlien tJiey are not unconimoi. upon our coasts. [Tiiey have large win-s, and fly strongly, 

 I>nt in conseqaenec of the position of the feet, the tibia being qnire buried ^^lrhi^ the in'tcgmnents, 

 are unable to walk, tlioiiLdi they ])u.h Ihcmselves forward with facility and tolerable speed, trailing 

 upon the belly. They have a short tail, on the tripod of which and the feet they are enabled to 

 .stand upright, and take a wide view around tliem by means of their long neck : they utter dismal 

 lifju lings ; and produce large spotted eggs, two or three in number, which are extremely unlike those 

 of the Grebes. 



Tln-ep specif :s are weil known, the whole of which are not rare in Britain. One, as hirge as a Goose {Col. gla- 

 ciafK-.'), the CuUiired Loon, hiack above, beautifully spotted with white, with a nearly ])erfeot collar of the same 

 round the neck, and a black head. The second, {C. glaciulLs), the Black-throated 

 Loon, extremely variable in size, hut always smaller than the precedinp:, with a fu)i- 

 i^inous grey head, and larger white spots on the upper parts : both of which species 

 liavf the inmiature plunuis;e dusky above, with greyish edgings to the feathers : and 

 the Red-throated Loon {C. scjitentrluncdis), still smaller and much commoner, the 

 winter dress of which (and not the immature plumufre, which resembles that of the 

 others, is speckled above with numerous small whitih;h spots bortleriuj^ the featliers, 

 which wear off in spring, leaving the back spotless blackish ; coim.-ident witli which 

 change of appearance, a rufous patch appears in front of the neck. All three are 

 great destroyers of fish, and proceed with extreme swiftness under water, in general 

 making little use of their wings to assist their progress. They are common to the 

 northern regions of both continents, as are also the four fii'st-inentioned Grebes.] 



TriE Guillemots (Uria, Brisson & Illiger), — 

 With the general form of the beak of the preceding, have it covered with 

 feathers as far as the nostril, and cmarginated at the tip, which is a little 

 arcuated. Their principal distinction, however, ccnisists in wanting the 

 Ijack-toe. Their wings, much shorter tlian tho^e of the Loons, iiarely sulHce 

 for the function of flying. They feed on hsh and crustaceans, and are found 

 about the precipitous rocks on which they breed. 



[These birds, the first of which is merely an Auk with a more slender bill, fly with considerable swiftness in a 



struij^ht iiiie, thrii- wings being reduced to the miniumm extent adequate for aeriul support, in order that they 



[night be more efficient under vrater, where no use whatever is made of the feet, 



which are held out like those of a wading bird when cleaving the air. Ac- 



cnrdiugly they literally fly under water, wheicas the subaquatic progression of a 



("iridje more resembles that of a Frog, and the Lnons do not generally use the 



\\ ings at all : hence the prolongation forward of the fixed patella, so considerable 



in the Loons, which is reduced in the Grebes, and entirely wanting in the Auks, 



Pufllns, and Gnillemots, which form a particular group, found only in the ocean. 



'I lie hdter have also smaller coeca, a particularly tough cuticular lining to tlie 



stoniai.h, of a bright yellow colour, a different sternal apparatus, which most 



nearly approximates that of the Loons, diverse plumage and seasonal changes, 



S:c. They are pre-eminently reniarkable for the manner in which the skeleton 



incloses the viscera as in a box, in order to resist the pressure of deep water; 



while their air-cavities are unusually large, which causes them to float very high 



when on the surface, and are obviously designed to increase the standard of 



respiration so as to permit of their sustaining themselves in the air with their 

 short and r.an-ow wings, tliese, however, not being violently beaten m the act of 



flying. Their movements under water precisely resemble those of the D'/tirU/.r, 

 or common Water Beetles ; the principal motion being more or less veriical, in- 

 stead of horizontal as in the Grebes and Loons : they are, therefore, togetlier with 

 the distinct group of Penguins, the most characteristic diversofthe class. 



One common on the precipitous coasts of all Britain, is the Common Guillemot 

 (U. troile), of a dusky slate-colour above, white beneath, and a bar of the ^ame on 

 the wing, formed by the tips of the secondaries; the throat black in sumjiier, 

 \ihite in winder. It lays oidy one e'^^, of enormous ]irnprir(ifuial magnittnl-'. ana remarkably variable in colour. 

 The ynnng at flrst resemble the adults in summer dress; but their flrst jihimage, which succeeds the down, and 

 the texture of which is singidarly delicate, presents the colouring of the adult winter-garb, and is exchanged for 

 the hii-ter in the eouisc of a few weeks. They breed in vast numbers on the narrow ledges of rocks where in 

 many places they are seen sitting in successive rows, one over another. In aidumn they nii-'rate southward 

 those which breed on the British shores being replaced by others from more northern latitudes. 

 Another and smaller siieeies, is the Black Guilleinot {U. gn/Ue), entirely black, with a groat white wing-spot, in 



