Assertion: barn owl's feather | /r/AtLocation | present species
Facets:
Source sentences:
text: A character by which they may always be distinguished is found in the operculum, the feathers margining which are in the present species reduced to their tubes, the shafts and filaments being wanting, whereas in the European species each tube bears a very slender shaft, about half an inch long, and furnished with about half a dozen filaments on each side.