Oherholser—Review of the Plover Genus Ochthodromus 513 
the proportions of bill, feet, wing, and other parts. The shape 
of the tail does not seem to be a good character, since it is var¬ 
iable and not well correlated with other differences. The regu¬ 
larity of the tarsal reticulation, made use of in one or two in¬ 
stances by Mr. Mathews, does not seem to be either definite or 
constant enough for a generic character. Neither is mere size 
alone a satisfactory generic distinction. Nor does the present 
writer regard color pattern as a better, or even so fundamental 
a generic basis as structural differences. Furthermore, it does 
not seem to me at all advisable to separate generically species 
which differ only in color or color pattern. Mr. Pycraft’s ex¬ 
cellent remarks on this subjecP should be read by everyone in¬ 
terested. 
The measurements of which use is made in proportional com¬ 
parisons in this paper have been taken as follows: 
Length of wing .—The distance from the bend of the wing to 
the tip of the longest primary, taken with dividers without 
straightening the quills. 
Length of tail .—The distance from the coccygeal insertion of 
the middle feathers to the tip of the longest rectrix. 
Length of head .—The distance from the point where the 
feathers of the forehead end on the culmen to the hindmost 
point of the skull, taken in a straight line with dividers. 
Exposed culmen (length of hill ).—The chord of the culmen, 
taken from its tip to the point where the feathers of the fore¬ 
head impinge on its base. 
Height of hill at base .—The distance in a straight line from 
the base of the exposed culmen to the nearest point on the ramus 
of the mandible. 
Width of hill at loral feathering .—Measured with dividers at 
the point on the side of the bill where the loral feathering ends. 
Length of dertrum .—Measured in a straight line from the 
posterior end of the dertrum to its tip. 
Length of tarsus.~A straight line from the center of the heel 
joint on the posterior side to the middle of the joint between 
the metatarsus and the middle toe on the anterior side. 
Middle toe without claw .—Measured along the upper side from 
the middle of the joint between the metatarsus and the middle 
toe to the base of the uncovered portion of the claw. 
Brit. Ornith. Club, XXXV, February 27, 1915, pp. 70-74; 85. 
33 — S. A. L. 
