BIRDS — T Y RANNINAE — CONTOPUS. 187 
Comparative measurements of species. 
Catal. 
No. 
Species. 
Locality. 
Sex. 
Length. 
Stretcl) 
Wing. 
Tail. 
Tarsus. 
Middle 
Its claw 
alone. 
bu. 
above. 
Along 
gape. 
Specimen 
measured. 
942 
8 
6.80 
7.50 
6.66 
7.75 
4.26 
3.30 
0.54 
0 64 
0.22 
0.64 
0.90 
. do 
13.25 
4.33 
Fre>h .... 
7205 
do 
Slioalwater bay,WT 
4.20 
3.06 
0.56 
0.64 
0.22 
0.70 
0.94 
13.00 
Fresli 
2962 
55U 
Contopus richardsonii. . 
Colorado river, 0. T. 
Q 
8 
8 
5.86 
5.82 
3.26 
2.64 
0.50 
0.50 
0.16 
0.70 
3.42 
2.70 
0.50 
0.52 
0.20 
0.50 
0.76 
Dry 
2041 
do 
6.30 
6.02 
3.51 
3.00 
0.51 
0.46 
0.18 
0.52 
0.76 
Dry 
9105 
3.38 
2.76 
0.50 
0.50 
0.16 
0.48 
0.70 
2255 
Contopus virens 
8 
5.00 
6.16 
3.38 
2.66 
0.50 
0.50 
0.20 
0.48 
0.70 
Dry 
10.75 
10.00 
3.50 
3.14 
3.17 
Fresli .... 
1632 
An 
T 
5.20 
6.16 
2.66 
0.50 
0.46 
0.16 
0.50 
0.70 
Fresh .... 
7247 
do 
5.80 
3.34 
2.76 
0.51 
0.46 
0.20 
0.48 
Dry 
7944 
5.90 
3.36 
2.74 
0.50 
0.46 
0.20 
0.48 
0.72 
GENERAL REMARKS. 
There is, perhaps, no group in ornithology, certainly none among American hirds, the species 
and genera of which are so difficult to determine as those of the small olivaceous flycatchers. 
The variations of size, color, and proportions are generally very slight, (though constant,) and 
only to be appreciated after a close examination and actual comparison of specimens, as well as 
long familiarity with the subject. Very few of the older authors describe the species so that they 
can be recognized at all, and the identification is usually made from statement of locality, habit, 
or common name. Wilson was the first to give accurate and intelligible descriptions of the 
species inhabiting the United States, and it would have avoided much confusion if they had 
been actually the first presented to the world. 
In comparing the small North American olivaceous flycatchers together, usually known as 
species of Tyrannula, I find two well marked groups worthy of generic separation : one with 
short legs and pointed wings, the other with longer legs and rounded wings. In this, however, 
it becomes a question what is to be done with the old name. The type of Tyrannula, Swainson, 
(1827,) is the Musaicapa barbata of Gmelin, a species with a yellow spot in the middle of the 
crown, and the rump yellow, the bill very broad and with the bristles equalling it in length. 1 
All these characters, and others, are entirely different from those attaching to our species, and 
the same generic name cannot be used for them without great impropriety. 
The same objections apply to 31yiobi.us of Gray, (1838,) this being a simple substitute for the 
Tyrannula, supposed to be nullified from its resemblance in sound to Tyrannulus of prior date. 
The two names, however, are sufficiently distinct to involve no difficulty in their use. 
Reichenbach makes numerous species among the Tyranninae, (Avium Systema Natune, plates 
65, 66, 67,) but, as far as I can judge from his figures, none are applicable here. In the 
1 Tyrannula barbata, Swainson. 
Muscicapa barbata, Gm. I, 1788, 933.— Latham, Ind. Orn. II, 1790, 488. 
Muscipeta barbata, Pr. Max. Beitraige, III, 9.34. 
Tyrannula barbata, Swainson, Zool. Jour. Ill, Dec. 1827, 359. 
Myiobius barbalus, Burmeister, Thiere Bras. II, 1856, 501. 
Platyrhynchus xanthopygius, Spix, Av. Bras. II, pi. ix. 
Hub.— Coast region of Brazil, according to Burmeister, from whom most of the preceding synonyms and the indications of the 
species are cited. 
