STUDIES OF THE MACRO CHIEES. 
335 
is really the case, that the osseous hyoid arches of these several 
types are also of very different patterns, and do not suggest to 
us any special relationship of their owners. 
To sum up then, so far as the skulls of these birds are con- 
cerned. Had we no other part of their structure to guide us, 
I think we should be fully justified in placing them in separate 
orders of birds. But let us still further compare the charac- 
ters of their osseous structures and pass to a consideration of 
the remainder of their asial skeletons. 
First let us take a glance at the number of vertebrae in the 
spinal columns of the several birds in question, irrespective of 
any special characteristics these vertebrae may possess in them- 
selves. For I wish it to be distinctly understood that although 
Species. 
Number of verte- 
brae in the cervi- 
cal portion of the 
column that are 
without free ribs. 
The first vertebra 
that bears a pair 
of free ribs. 
The first vertebra 
whose ribs con- 
nect with the ster- 
num by costal ribs. 
Trogon mexicanus j 
12 
13th 
(without unciform 
processes). 
14th 
Chordeiles texensis j 
11 
12th 
(with unciform 
processes). 
13th 
(14th in 
P. Nuttalli). 
Geococcyx californianus ... 
12 
13th 
15 th 
Species 
Trogon mexicanus. 
Chordeiles texensis 
Geococcyx californianus 
Number of dorsal 
vertebras con- 
necting with ster- 
num. 
4 
(and one more 
dorsal vert, that 
does not so con- 
nect, making 5 
dorsals). 
3 
(and one more 
dorsal vert, that 
does not so con- 
nect). 
No. of vert, in 
sacrum and the 
sacral ribs. 
12 
There is one pair 
of sacral ribs. 
10 
sacral ribs join 
sternum. 
11 
No. of free tail 
vertebrae, includ- 
ing pygostyle. 
(5 in the Whip- 
poor-will) 
