NATURAL SCIENCES OF PHILADELPHIA. 
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2. Bill decurved ; tibia much exposed. 
Bill compressed ; legs long, slender ; middle toe 
not quite three-fourths the tarsus, Ancylocheilus. 
Bill depressed ; legs moderate, stout ; middle toe 
nearly or about equal to tarsus, Pelidna. 
II. Bill equal to the tarsus. 
Tarsus equal to middle toe, Actodromas. 
The most natural succession of the genera appears to be that presented 
above, viz. : Micropalama, Ereunetes , Tringa, Calidris, Arquatella, Ancylo- 
cheilus, Pelidna , Actodromas. Micropalama , in its long, slender, sensitive bill, 
somewhat furrowed culmen and digital web, seems to form the natural con- 
necting link between Scolopacece and Tringece , through Macroramphus . 
Ereunetes is next most closely allied, having also the membrane to the toes ; 
but here the bill and feet are shortened, and have nearly the proportions of 
Tringa , which most naturally succeeds. Calidris is in all essentials like 
Tringa , except the absence of the hind toe. In Arquatella the bill is some- 
times very slightly decurved ; in Ancylocheilus and Pelidna it is successively 
more so. In the latter the middle toe becomes nearly or quite equal to the 
tarsus, opening the way for Actodromas , where the slender, attenuated bill, 
and much denuded tarsus, seem to lead directly to the Totanince. 
If so great a subdivision of the Tringece as is here presented be objected to, 
it is replied that the variations in external form are so great that a single 
genus, in the modern acceptation of the term, cannot contain them all ; and 
if more than one genus be adopted for those with fully-cleft anterior toes, it is 
not easy to stop short of the number here adopted. Ornithologists have 
indeed perceived how unnatural was the association of all the species under 
Tringa , and at different times, some of them very early, names have been 
proposed for all the groups. As early as 1800, the absence of the hind toe 
caused Calidris to be separated ; and, in 1811, the webbed feet of Ereunetes 
were made the grounds of generic distinction. Pelidna of Cuvier, instituted 
in 1817 for the slender-toed smaller Sandpipers, was a further attempt at 
division ; but that genus, as left by its author, still contained species very 
dissimilar ; and, in 1829, Ancylocheilus and Actodromas were characterized. 
The great peculiarities of Tringa himantopus Bon. caused it, soon after its first 
discovery, in 1828, to receive subgeneric distinction from Tringa. It was not, 
however, till 1858, that Arquatella , a peculiar form, was characterized. But 
while in other groups, particularly among the smaller land birds, the divisions 
have been minute and greatly extended, there seems to have been a general 
reluctance on the part of ornithologists with regard to recognizing these 
divisions. It may be that in this group Nature allows more external varia- 
tion in forms very closely allied than is usual ; but until this is proved to be 
the case, it seems necessary, to keep pace with the progress of ornithology, to 
consider the characters of the different sections as of full generic value. 
Having, it is thought, dwelt sufficiently upon the general features of the 
group, we proceed at once to characterize the different genera and species. 
MICROPALAMA Baird. 
Hemipalama , Bonaparte, Syn. 1828, 316. Typus Tringa himantopus , Bon. nec 
Bon. Obs. Wils. 1825. (Typus T. semipalmata , Wils.) 
Micropalama , Baird, Gen. Rep. 1858, 726. Typus T. himantopus , Bon. 
Char. Bill long, equalling the tarsus, straight or very slightly decurved, 
slender, very much compressed, tip much expanded and vascular for some 
distance. Culmen on the terminal half depressed, with two rudimentary, 
longitudinal furrows. Groove on the lower mandible narrow and indistinct. 
Wings moderate, pointed, first primary a little the longest. Tail of twelve 
1861.] 
