No. 1.] SPEOTYTO CUNICULARIA HYPOGAA. 117 
Strong “crural” and “humeral” tracts characterize the 
pterylography of Speotyzo, the feathers of the latter being very 
long and large. The femoral pterylee are fairly well pronounced 
in this owl, and a few scattered feathers may occur beyond it, 
as do a few between the limbs of the bifurcation of the spinal 
tract, though these latter are inclined to be of the downy variety. 
This description goes to show, then, that Speotyto has a ptery- 
lography, in some particulars, quite its own, though it is possible 
that it may largely agree with such genera in this respect, as 
Glaucidium and Micrathene, but I have not specimens of these 
at my hand at present, wherewith to compare it. Speotyto has 
no ear-valve, and a few delicate feathers are distributed over the 
eyelids. As compared with the species of owls described by 
Nitzsch, its pterylography is peculiar in the marked and unusual 
breadth of the tracts, and in that the head is completely covered 
with feathers upon all its aspects. 
On CERTAIN STRUCTURES OF THE HEAD. 
Seven or eight years ago the writer published a detailed 
account of the skeleton of the Owl we now have under consid- 
eration, so that we will not be required to touch upon that part 
of its anatomy here, or only in so far as some special point 
seems to demand it (U. S. Geol. and Geogr. Survey of the Terr. 
Dep't of the Interior. ayden’s 12th Ann., pp. 593-626, 3 
pls.). Upon removing the teguments of the head, we are to 
note that the moderately large eyes of Speotyto look forwards 
and outwards, but do not project as prominently as we find 
them sometimes in other Strzgide. The nictating membrane is 
attached in the usual manner to the antero-superior part of the 
eyeball, which latter possesses a deep encasement of sclerotal 
plates. As in most Owls, the frontal region of the cranium is 
narrow, and the sapraorbital processes are spiculiform, projecting 
backwards and a little outwards; to the inner side and apex of 
either of these, and to the entire posterior orbital margin, is 
attached a dense, fibrous membrane, which covers the globe of 
the eye posteriorly, being inserted finally to the cranium in 
front of the ear, to the zygoma slightly, and to the under side 
of the eyeball, upon which, throughout its extent, it is drawn 
tightly down. 
