A4 MAMMALS

for a run, standing on their hind legs, holding their
arms up in the air, and bending their tails up into a
double curve. The owl-faced monkeys, or dourou-
colis, have very long tails, but the tails are not pre-
hensile ; neither are those of the squirrels, or saimaris,
and the titis, which are often classed together.
These monkeys are much smaller as a rule than any
of the preceding, and they vary very much in the
length of their tails. The sakis also do not have
prehensile tails; the uakaris have hardly any tail at
all, but the howlers have very long tails and these
are prehensile. On the tail alone they would be
classed next to the spiders ; but the expansion of the
hyoid bone, which particularly distinguishes them, is
so clearly foreshadowed among the titis and sakis
that these genera have to be placed between. This
bone, which joins on to the upper part of the wind-
pipe, is a most extraordinary-looking thing ; there are
some good specimens of it in the Kensington Natural
History Museum—bony bags as thin as paper and as
large as an ordinary wine-glass, a mouth-organ of
great capacity for the production of the exasperating
music which has given the genus the name of MMycetes,
or moaners.

The best known of the capuchins is perhaps the
brown one (C. fatuellus),a representative of which
was experimented on by Dr. Romanes, who published
the diary of the proceedings in his Amdmal Intelli-
gence. We must find room for an extract from this
most interesting record. ‘To-day he obtained posses-
sion of a hearth-brush, one of the kind which has the
handle screwed into the brush. He soon found the