252 AVES, 



greater number of them are also feeble fl3ers, and several are quite deprived of that faculty, in 

 consequence of the shortness of their wings, they may be regarded as exclusively attached to the 

 surface of the watsr : their plumage is particularly dense, and its surface frequently pohshed, 

 presenting a silvery lustre. They swim under water by the aid of their wings, which are 

 employed as fins. Their gizzard is tolerably muscular ; the cceca of moderate length. They 

 have onlv one special muscle on each side of their lower larynx. Such are 



The Loons {Colymbus, Lin.), — 

 Which are characterized by a smooth, straight, compressed, and pointed bill, with linear nostrils ; but 

 require to be subdivided from characters derived from the feet [the entire skeleton, character of 

 plumage, propagation, &c. &c.] 



The Grebes {Podicq)s, Latham ; Colymbtis, Brisson and lUiger), — 

 Instead of ordinarj- webs between the toes, have the latter widened as in the Coots, and the anterior 

 connected only at base by membranes, [which border the remainder] . The claw of the middle toe is 

 flattened ; the tarsi exceedingly compressed. The semi-melallic [or satiny] 

 lustre of their lower plumage has led to the occasional employment of it as 

 fur. Their tibia, as also that of the Loons [in which it is much more pro- 

 duced,] is prolonged forwards beyond the joint, to give a more efficient 

 insertion to the extensors of the leg. [Sternum (fig. 123)* very short, 

 and of peculiar conformation, approaching in some respects to that of 

 the Cormorants ; which these very singular birds also resemble in the 

 character of their eggs, the hard shell of wliich is invested with an ab- 

 sorbent chalky substance. They have no vestige of a tail. The young are 

 clad in exquisitely soft down, which is striped black and white, as in the 

 Emeu. The constant number of cervical vertebrae is nineteen instead of 

 thirteen, as in the restricted Loons ; and their skeleton is altogether 

 extremely different.] 



These birds reside in lakes and ponds, and nestle among the rushes, 

 [producing numerous eggs, whereas the Loons lay very rarely more than 

 two]. It appears that under certain circumstances they carry their young 



Fift. 123. — Sternum of Grebe. . . _, . . , , , i_ -^i r^i 



under then" wings. Their size and plumage change so much with age [the 

 latter rather according to season], that naturalists have very much multijilied the species. M. Meyer 

 reduces those of Europe to four, [instead of five, which is the right number, as foUow] : — 



The Crested Grebe (P. cristatus).—As large as a Duck, and satiny-white, vith dusky upper-parts, acquiring with 

 age a double black crest, and rufous collar edged with black, [which exist only during the breeding season]. 



The Red-necked Grebe (P. ritbricoUis).—Sma\\eT, with the neck bright rufous, and greyish collar less developed. 



The Horned Grebe (P. cornutus) fand Eared Grebe (P. anntus).—it\\\ less, and precisely of the same size with 

 each other, so that they can only be distinguished, when the seasonal collar falls, by the beak of the second being 

 distinctly a little recurved, and by a difference in the colour of the iris of the recent specimen ; their collars, how- 

 ever, during the breeding season, are very different, and that of the Eared Grebe is less developed than in the 

 other]. 



The Little Grebe (P. »n/no?-).— Size of a Quail, with never any crest or collar. [These various species, notwith- 

 standing the shortness of their wings, can fly w ith considerable speed, when they once fairly rise, which they do 

 with unwillingness, and seldom except when compelled to migrate. They can walk with their feet, and do not 

 trail upon the belly, like the Loons ; and when under water, they make more use of their wings than the latter do 

 habitually]. 



The Finfeet {Heliornis, Bonatcrre ; Podoa, Illiger) — 

 Have feet lobed as in the Coots and Grebes, but their tail is more developed than in either, and their 

 claws sharper. 



Such is Plotus surinmnensis, Gmelin ; and Heliornis senegalensis, Vieillot, which Gmelin approximated to the 

 Anhingas. 



The Loons {Columbm, Latham; Mergus, Brisson; Eudytes, Illiger), — 

 With all the [external] form of the Grebes, have the feet webbed in the ordinary manner ; tliat is 

 to say, their three front toes are connected by membrane to the tips, and are all terminated by 



• The representation (fig. 123), in otlicr respects accunle, is >ume«ii;it loo lon^'.— Ko. 



