1900.] SHUFELDT—-OSTEOLOGY OF THE STRIGES. 667 
same applies to the thirty figures given on the Plates. In fact, in 
the case of the latter no one of them has ever been given before in 
any memoir anywhere. For the first time now we have here the 
relations of the cranial segments at the base of the skull in the nest- 
ling Budo ; the internal view of the skull in the adult ; the cranium 
of Megascops and skeleton of JZcropadias figured, and a good many 
other specimens of the bones of Owls which have never been pub- 
lished before. It is believed that these will be found to be useful 
not only to the comparative osteologist, but to the researcher in the 
fields of avian paleontology. Further, it will be found that in the 
present memoir descriptions have been given and intercomparisons 
made of the osteological characters presented on the part of many 
of the species of the genera of Strzx, Asio, Surnium, Scotiapex, 
NVyctala, Megascops, Bubo, Nyctea, Surnia, Speotyto, Glaucidium 
and Micropallas, the whole being completed with a brief discussion 
of the probable affinities of the Stzgz¢@ and their place as a group 
in the system. 
WasHINGTON, D.C., November 21, 1900. ROWS: 
Owls of a number of genera, represented by a variety of species, 
are to be found in the avifauna of the United States. That North 
American alucoline type of the Barn Owls, Six pratincola, ranges 
throughout the southern and warmer parts of the country. The 
genus Aszo is represented by two species, Syruzum by two and a 
subspecies, while far north Scotiapex cincrea and Scotiapex c. lap- 
ponica are occasionally found. Of the smaller Owls, Vyctala is 
represented by one species and a subspecies, the best known one 
being WV. acadica, now becoming quite rare. Screech Owls of the 
genus J/egascops are especially numerous and of wide geographical 
range, ornithologists having recognized at the present time two 
species of them and at least half a dozen subspecies, but some of the 
latter require an eye highly educated in the matter of the fine dis- 
crimination of shades of color to distinguish them. 
Great Horned Owls of the genus 40 have the well-known Budo 
virginianus, of which there seem to be at least three fairly well- 
marked geographical races or subspecies—a Western one (swbarc- 
ticus), one in the Fur Countries (arcticus), and a Northwest Coast 
region variety, which has also been taken in Labrador (sa/uratus). 
We also have the magnificent Snowy Owl (WVyctea nyctea), as well 
as two Hawk Owls (Suwrnia), and those other Owls, known as 
PROC. AMER. PHILOS. SOC. XXxIx. 164. RR. PRINTED JAN. 19, 1901. 
