STUDIES OE THE MACROCHIRES. 
299 
Studies of the Macrochires, Morphological and otherwise, with 
the view of indicating their Relationships and defining 
their several Positions in the System. By R. W. Shueeldt, 
M.D., C.M.Z.S., Captain, Medical Corps, U.S. Army. 
(Communicated by W. K. Parker, F.R.S., P.L.S.) 
[Read 19th January, 1888.] 
(Plates XYII.-XXIY.) 
It may be remembered by those who are interested in the 
structure and classification of birds that I published, in the 
‘ Proceedings’ of the Zoological Society for 1885 (pp. 886-915), 
a memoir entitled “ A Contribution to the Comparative Osteology 
of the Tro chili dee, Gaprimulgidce, and Gypselidce” That memoir 
professed to be but little more than a mere introduction to 
a subject which I will here enter upon more fully, although the 
opinions there set forth are, in the main, substantially those that 
I still hold, at least in the case of the TrocMlidce and Capri- 
mulgidce. Since the date of that paper, however, I have never 
ceased in my endeavour to gather together the necessary material 
for this, my second contribution on the subject ; and, as will be 
seen by the list of specimens in the subjoined Table, these efforts 
have met with a very fair measure of success. 
In the conclusions at the close of my former paper I contended 
that all the existing Caprimulgine birds of the world’s avifauna 
should be grouped in one order, the Caprimulgi. In this 
group, no doubt, would fall Nyctibius and Steatornis , and very 
probably Podcirgus and Psalurus. Further, I proposed that the 
Humming-birds should constitute another order, to be known as 
the Trochili. I made no final determinations in regard to the 
Swifts, beyond that they should be separated from the Trochili ; 
but these birds will be carefully studied in the present memoir, 
and my opinions in regard to them stated in the conclusions 
which close it. 
Finally, I had something to say about certain apparent resem- 
blances between the bones in the roof of the mouth of a Trogon 
and the corresponding structures in a Humming-bird. But my 
remarks were only drawn from a paper by W. A. Forbes published 
in the ‘ Proceedings ’ of the Zoological Society three or four years 
LINN. JOURN. — ZOOLOGY, VOL. XX. 21 
