106 SHOUFELDT. (VoL. III. 
the humerus (and sometimes the femur?) is always pneumatic, 
and in Myzarchus a single row of quite sizable foramina extend 
the entire length of the middle line of the sternum adown its 
thoracic aspect. I am inclined to think, too, that other long 
bones in the skeleton of this species have the air admitted to 
the cavity of their shafts; but here I judge only from appear- 
ances ; for if the foramina be present, I failed to find them, even 
with the aid of a good lens, in some cases. 
With this succinct account of the osteology of some of the 
genera of our American 7yrannide, I will close the general de- 
scriptive part of my memoir, and pass to my conclusions, based, 
as these latter will be, upon the facts herein brought out. In 
this place, however, I would like to add that Iam aware that I 
have not touched upon the embryology of any of the species 
treated, nor was that my aim originally. The paper proposes 
nothing further than a general description of the skeleton in 
adult forms, and such deductions as we may logically make 
upon the comparison of such data. No doubt when we come to 
critically consider the embryology of many of the species, and 
draw more elaborate comparisons, a great deal of additional in- 
formation will be gotten at, and some of the more complex 
questions in affinities by such means be decided. Especially 
will this be true in the case of comparing the embryos of Zyvan- 
nide with those of the Lande and Setophaga and others. 
The most I can hope for the present effort, is to establish 
broad lines in the osteology of the Passeres of this country, and 
present a framework, as it were, which may serve as a basis 
upon which may be reared in the future those refinements in 
avian morphology, that forever tend to shed a more certain light 
upon all vexed questions in the taxonomy of this perplexing Class. 
CONCLUSIONS. 
For fully ten years past and more, the writer has busied him- 
self with the anatomy of the passerine birds of this country, 
during which time he has also read many of the works of others 
upon the same subject; so then, although this memoir deals 
alone with the osteology of the order Passeres, it is very likely 
that now we come to sum up our knowledge in these fields, and 
draw our conclusions, and offer our opinions as to classification 
and affinities, —it is very likely, I say, that we will not be en- 
