The crania of the Owls present many features of interest, which may
serve a good purpose in the definition of the sections and the genera,
and to which attention has been occasionally called in the preceding
pages. The tendency to asymmetry is especially marked in some species,
and the better to illustrate this and other features we append several
plates, in which the corresponding views are placed side by side.[39]
The figures and accompanying lettering tell their own story, without any
necessity of a labored description.