156 OJf THE CLASSIFICATION OF BIBHS. 
more instances of the disappearance of the hind toe than 
elsewhere : in this order, also, we have some very remark- 
able forms, by which the passage from the simply wehhed 
shape to the swimming foot is gradually and distinctly 
marked. The typical structure is found in the sand- 
pipers ( Tringa), ta tiers ( Totanus), and snipes ( Smlopax ) . 
In these the three anterior toes are very long, slender, 
and deeply cleft to their base, and the lateral ones not 
much shorter than the middle j the hinder toe is much 
shorter, proportionably, than in the Rasores, and is placed 
rather higher up the leg. The haUux, in fact, in all the 
above genera, and in most of the others, is obviously 
rudimentary, and therefore can in no wise be depended 
upon even as a distinction for a genus, notwithstanding 
the undue stress that has been laid upon it in two or 
three instances in the Regne Animal. But, as we quit 
the typical waders and approach the swimmers, we 
meet with feet totally different ; the most remarkable of 
these forms characterise the Phaleropes, the coots, the 
jacanas, and the rails ; the two first are 
swimmers, the latter walkers. There 
may be observed in some of tlie tatlers a 
projecting margin or rim on each side of 
the anterior toes, which appears to indicate 
in birds so formed, some little power 
of swimming; now this margin appears 
the first, or incipient development of the 
lobed foot of the Phahrojm hyperborem 
{fig- 85.) ; the margin gradually enlarges in 
Ph. Wilsoni*, and the toes are connected 
at their base by a short web; a structure, as Dr. Rich- 
ardson well observes, which seems to fit it more for 
walking on the surface of marshes filled with aqua- 
tic moss {Sphagna;), than for exercising the full powers 
of swimming possessed by Ph. hyperboreus, and Fuli- 
carius. In these two species the membrane on each 
side the toes is not only enlarged, but divided into dis- 
tinct lobes, or deeply scalloped membranes ; the webs 
* Northern Zoology, vol. it p. 405. pi. 69. 
