88 SHUFELDT. (Vou. III. 
foramina — the interdiapophysial vacuities among the uro-sacral 
vertebrz. Viewed laterally, we observe that the obturator for- 
amen and the circular acetabulum are of nearly the same size, 
while the sub-elliptical ischiadic foramen is about five times as 
big as the last-mentioned aperture. The obturator space is 
closed in front, but open behind where the ischium is simply 
tangent to the slender end of the post-pubis. As near as I can 
tell from the pelvis of an adult Sza/za, there appear to be eleven 
vertebrze fused together to form the pelvic sacrum, and they are 
peculiar in having their common centra flattened upon the ven- 
tral aspect, and marked by a double longitudinal row of little 
squarish pits, from the first to the seventh inclusive. 
The first three sacral vertebrze (dorso-sacral) throw out on 
either side strong diapophysial braces which abut against the 
ilia ; the two succeeding vertebrze lack these, they are aborted ; 
in the sixth and seventh they are long and slender, and again 
reach out to the ilia as supports opposite the acetabule. Thus 
we see that these birds possess a good average passerine pelvis, 
and as we proceed occasion will be taken to point out the differ- 
ences existing in other types and species. 
Szx free vertebrz and the terminal pygostyle constitutes the 
skeleton of the tail in Sza/za, in all of the specimens I have thus 
far examined. 
Members of this genus possess a sternum of a typical passer- 
ine pattern, and so well-known is this that it requires no special 
description from me here. This pattern, I would incidentally 
remark, — for we will be obliged to return to this subject again in 
the present memoir, — varies but slightly throughout the entire 
order of passerine birds, and is markedly uniform in its shape, 
so that a true species of this enormous group can be diagnosed 
almost in an instant, and to a certainty by a glance at its ster- 
num. Sir Richard Owen called it the ‘“ cantorial sternum,’ ! but 
this is hardly the proper appellation to apply to it, because the 
pattern is almost identically the same in the clamatorial birds, 
and they do not sing. (See Fig. 20 of the second Plate to the 
present paper.) 
In Merula, the form of the sternum departs but little from 
the bone in Szalia ; the “body” perhaps being a little narrower, 
1 OwEN, R., Comp. Anat. and Phys. of Verts., Vol. I1., p. 20, Fig. 15. 
