194 GENERAL ORNITHOLOGY part ii 



to the end of the first, or along part of the second, phalanx of the 

 toes ; usually farther between the outer and middle than between 

 the middle and inner toes. Such a foot is well illustrated by the 

 semipalmated plover ^gialites semipalmatus), semipalmated sand- 

 piper {Erewnetes pusUlus, Fig. 48), and willet (Symphemia semipalmata, 

 Fig. 49). In a few wading birds, as the avocet and flamingo, the 

 webs extend to the ends of the toes. This introduces us at once to 

 the third main modification of the foot. 3. The natatorial type. Here 

 the foot is transformed into a swimming implement, usually with 

 much if not entire abrogation of its function as a hand. Swimming 

 birds, with few exceptions, are bad walkers, and few of them are 

 perchers. The swimming type is presented under two principal 

 modifications : — (a.) In the palmate or ordinary webbed foot, all 

 the front toes are united by ample webs (Fig. 50). The palmation 



-, „ Pig. 49. — Seinipal- 



iiG. 4S.— Semipalma- mated bases of toes 



tion in Ereunetes; nat. of Symphemia; nat. Fig. 60.— Palmate foot of a tem, 



^'^^- size. Sterna forsterl; nut. size. 



is usually complete, extending to the ends of the toes ; but one or 

 both webs may be so deeply incised, that is, cut away, that the pal- 

 mation is practically reduced to semipalmation, as in terns of the 

 genus Hydrochelidon (Fig. 51). The totipalmate is a special case of 

 palmation, in which all four toes are webbed ; this characterises the 

 whole order Steganopodes (Fig. 52). (5.) In the Mate foot, a paddle 

 results not from connecting webs, but from a series of lobes or flaps 

 along the sides of the individual toes; as in the coots, grebes, 

 phalaropes, and sun-birds (Heliornithidce.) Lobation is usually 

 associated with semipalmation, as is well seen in the grebes 

 {Podicipedidm). In the phalaropes {Plmlaropodidm, Fig. 53 his) lobar 

 tion is present as a modification of a foot otherwise quite cursorial. 

 The most emphatic cases of lobation are those in which each joint of 

 the toes has its own flap, with a free convex border; the mem- 

 branes as a whole therefore present a scolloped outline (Figs. 53, 53 

 Us). Such lobes are merely a development of certain margk ' 



