172 
PROCEEDINGS OF THE ACADEMY OP 
longer than the middle toe and claw. The toes are usually long and slender, 
more or less margined at the sides, and flattened underneath ; free at the base, 
or with a very rudimentary membrane, except in Micropalama and Ereunetes . 
The lateral are nearly equal to the middle, the outer slightly longer than the 
inner. The hind toe is present, except in Calidris. The claws vary con- 
siderably in length, acuteness and amount of curvature, but they are always 
dilated on the inner edge. 
With respect to coloration, the Tringece of North America, with scarcely the 
exception of Arquatella maritima , present a general similarity in the pattern 
and disposal of the markings of most of the parts. The feathers of the upper 
parts have their centres very dark, and are margined with some shade of red- 
dish, yellowish, or white, the color being deepest on the scapulars. The 
primaries are uniformly deep dusky, without spots or bars, and are darkest at 
the tips and on the outer vanes. The shafts of all are white for some portion, 
usually the central. The secondaries are ashy-gray, bordered to a greater or 
less extent with white. The central tail feathers are usually considerably 
darker than the lateral ; but neither show any approach towards the trans- 
verse bars so universal among the Scolopacece and Totanince. Any attempt, 
however, at a generalization of the color of , the under parts seems impossible, 
since, as will be seen in the diagnoses of the species, they are found of very 
various patterns and colors. 
The species inhabiting North America are divisible into eight well-marked 
genera, among which are comprised nearly all the more important ones, 
though some, such as Eurinorhynchus and Limicola, have no representatives. 
The most extensive of these, Actodromas , seems to contain two well-marked 
groups, at least sub-generically distinct. Each of the others comprises but 
a single admitted North American species ; and of some, such as Tringa, 
Arquatella , and Ancylocheilus, but one species is at present known. The cha- 
racters of the most importance among the Tringece seem to lie in the legs. The 
proportions of tibia, tarsus and middle toe, and their relations to the bill, 
readily characterize definitely the groups. They are also the most constant, 
being subject to very little variation in each species. This is as might be 
expected, from their radical nature, since the most important and essential 
character in any group should be the least subject to variation. The bill, on 
the other hand, differs much in length in the same genus or species ; it reaches 
its maximum of variation in Ereunetes , and is most constant throughout the 
genus Actodromas. The wings and tail vary somewhat, but within very 
narrow limits. 
The North American genera of Tringece may be readily characterized by the 
proportions of bill, tarsus and toe, without reference to the tail or wings, though 
these of course furnish additional characters. The following schedule, in which 
the characters are purposely made as brief as possible, will serve to define 
the genera as adopted. 
Synopsis of Genera. 
A. Toes with a decided basal web. 
Bill equal to tarsus, both very long ; exposed portion 
of tibia equal to middle toe, which is not quite 
two-thirds the tarsus, Micropalama. 
Bill equal to tarsus, both moderate ; tibia exposed 
for two-thirds the middle toe, which nearly equals 
the tarsus, Ereunetes. 
B. Toes cleft to the base, or with a very rudimentary membrane. 
I. Bill longer than the tarsus. 
1. Bill straight ; tibia moderately or scarcely at all exposed. 
Tarsus longer than the middle toe, hind toe present, Tringa. 
As in Tringa ; hind toe absent, Calidris. 
Tarsus shorter than the middle toe, Arquatella. 
