44 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
the ombu, which is planted in front of many of the farm houses, and thence 
takes short flights in pursuit of insects. From the remarkable structure of its 
tail, the inhabitants of the country call it scissor-tail ; a name very well applied 
from the manner in which it opens and shuts the forked feathers of its tail. Like 
all birds thus constructed, (of which the frigate bird offers a most striking 
example), it has the power of turning very shortly in its flight, at which instant 
it opens and shuts its tail, sometimes, as it appears, in a horizontal and sometimes 
in a vertical plane. When on the wing it presents in its general appearance a 
caricature likeness of the common house swallow ( Hirundo rustica ). The 
Muscivora, although unquestionably belonging to the family of Muscicapidae 
manifests in its habits an evident relationship with birds of the fissirostral 
structure. 
Sub-Gen. PYROCEPHALUS, Goulb. 
Muscicapa. Auct. 
Muscipeta. Cuv. 
Tyrannula. Swain. 
Rostrum capite brevius, rectum, depressum, basi setis numerosis nigris obsessum ; 
mandibuld superiore emarginata , inferiorem obtegente ; naribus rotundatis patulis. 
Caput subcristatum. Alee longce ; remige prima secundum tertiamque longissimas 
subcequales fere cequante. Tarsi mediocres, anticb scutellati; digitis lateralibus ince- 
qualibus , exteriore longiore. Cauda mediocris quadrata. 
Mr. Gould observes, that “ the males of nearly all the members of this group 
(which may be considered either as a distinct genus or sub-genus of Myiobius), 
have the crown of the head and greater part of the under surface scarlet. Four 
species were obtained. — Pyrocephalus parvirostris,( Gould), and Muscicapa coronata, 
(Auct.), may be taken as types. 
1. Pyrocephalus parvjrostris. Goidd. 
Plate VI. 
Le Churrinche, Azara. No. 177. 
P. supra fuscus ; capite et subtus nitide puniceis ; rectricibus exterioribus tectricumque 
et secundariorum apicibus griseo-marginatis. 
Long. tot. 5^2 unc.; alee , 1 3 T V ; caudal, 2^; tarsi, ; rost. t 1 * * * * 6 j. 
Crown of the head, crest, and all the under surface, bright scarlet ; the remainder 
