Differs from the true _P. diadema_ in having the face slightly haired
between the eyes and on the chin; a patch on each flank rufous-white or
orange-yellow, separated by a reddish-black band; a spot at the root of the
tail bright rusty-red, and all the rest of body black, washed slightly with
rufous. The young are like the parents. This form is also of the {100}same
size as the type, but is a melanistic variety, for a series of specimens
show every intermediate shade between that here described and the BLACK
SIFAKA (_P. holomelas_), which is of an entirely black colour, and
inhabits, as has been shown by MM. Milne-Edwards and Grandidier, the same
region as _P. edwardsi_.
DISTRIBUTION.--The typical form of the species is confined to the extended
region on the east coast of Madagascar lying between the Bay of Antongil on
the north, and the River Masora in the south, in the forest-belts on the
eastern aspect of the mountains, where rain falls abundantly and the whole
region is covered with luxuriant vegetation. Its melanistic variety (_P.
edwardsi_) extends south from the Masora as far as the Faraouny river, but
it ranges to higher and colder altitudes on the mountains; while its
albinistic variety (_P. sericeus_) lives in the somewhat warmer region to
the north of Antongil Bay, each being, to south and north respectively,
conterminous with the central habitat of the typical form.