326 SHUFELDT. [Vo. II. 
up the pelvis in the Oyster-catcher, so that prolonged macera- 
tion does not tend to separate them. 
One skeleton of Hematopus at my hand shows a curious dila- 
tation of the latter third, or less, of the postpubis of the /eft side, 
not present in any other specimen, nor upon the opposite side 
of the same individual. All these points and characters are 
very different in the pelvis of the Surf-bird, wherein this bone 
is remarkable for its breadth, and for being, as it were, flattened 
out in the vertical direction, — shallowed ; its sides narrow, and 
ilia more or less spread. As among Plovers, and most or all 
Sandpipers, it shows a double row of interapophysial foramina 
down the sacrum (Fig. 21); and the anterior ends of the ilia are 
subtruncated and embellished with a delicately raised rim, 
nearly always to be seen in limicoline birds. Between the 
hinder ends of ilium and ischium, a rounded notch occupies the 
entire margin of the bone, which notch in Hematopus is angu- 
lated. Postpubis is in contact, more or less, for its entire 
length with the lower border of the ischium above it; and is 
carried beyond for some little distance to a pointed extremity, 
much the same being the case in the Turnstones. 
The ischiadic foramen is of considerable size, and of a subel- 
liptical outline; this vacuity being unusually large in an Oyster- 
catcher, and such a species as the Killdeer Plover. 
Without, then, further entering upon a fuller discussion of 
minor details, although they have all been carefully noted and 
weighed by the writer, I would state that in so far as the Hema- 
topodide@ are concerned, the pattern of the pelvis in that group, 
as represented by the bone from the skeleton of A. bachmant, 
is of quite a different style from the pelvis of either Aphrzza or 
Arenaria. That when we come to study the pelvis of A. var 
gata, and compare it with the bone in allied types, we discover 
that notwithstanding the fact that it exhibits many characters 
held in common by the limicoline forms generally, still it is 
impressed with a character of its own, being proportionately 
broader and shallower than the generality of either charadrine 
or tringine pelves. It is most nearly approached by the pelvis 
of a Turnstone, while this latter bird shows in its pelvis a marked 
shading towards the style of the bone in the Plovers. 
Again, Actztis and Afgialitis vocifera possess pelves almost 
identically alike in their general form; and in both these 
