The type of this species is in the India Museum, London. I t is quite distinct
from P. genibarbis, the typical example of which is in the same collection. The
latter is distinguished from the former and indeed from all the small flying squirrels
by its numerous and strong cheek-bristles, whereas there is no indication whatever
that those hairs ever existed in P. lepidus. Müller and Schlegel were under the
impression that the cheek-bristles of P . genibarbis were a character of youth, and
that P. lepidus was an animal of the same species in which these hairs had fallen out,
but P. lepidus is a smaller species than P . genibarbis. Moreover, there are certain
flying squirrels in which the cheek-bristles are entirely absent, and others in which
they are only developed to a limited extent, and some of the flying squirrels recently
described by Günther exemplify these differences which have also attracted his
attention.
This is one of the smallest of the Southern Asiatic flying squirrels. The upper
surface is pale yellowish-brown. The tail is markedly distichous, pale yellowish-
grey at its base, the remainder being pale brown and the under surface somewhat
rufous. The upper surface of the parachute is dark brown, the fore feet being pale
yellowish-brown, and the hind feet darker. The under parts are thickly clad with
rather woolly hair, white, but with a faint yellowish tinge. The bases of the hairs
on the sides of the belly and on the under surface of the parachute are slaty grey,
and on the outer half of the membrane they are almost wholly brown, tipped with
yellowish-white, but the dark colour is the prevalent tint. The moustache is long
and black.
The sides of the face and neck are yellowish-white.
Length of body 3‘90; tail 3'50.
There are four examples of this species in the Leyden Museum; it has hitherto
been found only in Java.
P t e b o m t s v o l a n s , Linnaeus,
jEcureuil volant de Siberie, Brisson, R£g. An. 1756, p. 159.
Polatouehe, Buffon, Hist. Nat. vol. x. 1763, p. 95.
The Sailing Squirrel, Pennant, Quad. 1792, vol. ii. p. 151 (in part).
Scivrus volanSjlArm. Syst. Nat. 12th ed. 1766, vol. i. p. 38; Pallas,Nov. Sp. Quad. Glirium, 1778,
p. 355; Zoograplr. vol. i. (ed. 1831), p. 190 ; Boddaert, Elench Animal, 1785, p. 120; Schreber,
Säugeth. vol. iv. 1792, p. 813, Tab. 223; Blumenbach, Abbeld. 1810, p. 71; Fischer, Syn.
Mamm. 1829, p. 364; Gray, List Mamm. B. M. 1843, p. 136; Schinz, Syn. Mamm. vol. ii.
1845, p. 58; Middendorff, Säugeth. Reise in Sib. 1851, p. 78; Schrenck, Reisen. Amur Land,
1859, p. 116; Radde., Reisen, in Sud. Ost. Siber. Säugeth. 1862, p. 131.
Pteromys russicus, Tiedemann, Zool. 1808, vol. i. p. 451.
Pteromys sibericus, Desmarest, Mamm. 1820, p. 342.
Pteromys volans, Fischer, Syn. Mamm. 1829, p. 365.
Pteromys vulgaris, Wagner, Schreber, Säugeth. Suppl. 1843,_vol. iii. p. 228.
Sciwroptera volans, Blyth, Joum. As. Soc. vol. xxviii. 1859, p. 278.
This northern form is quite as variable as the common squirrel with which
it is associated. I t is pale greyish-white; .the under parts white. Ears clad
externally and internally. No cheek-bristles; tail distichously bushy, and dusky
grey.
Inches.
Length of b o d y ....................................................................................................... 6*4
„ t a i l .......................................................................................................3-0
Northern Europe and Asia.
P t e b o m t s m o m o n g a , Temminck.1
Pteromys momonga, Temminck, Mamm. Fauna Japon. 1847, p. 46, pi. xiv .; Müller und Schlegel,
Verhandl. 1889-44, p. I l l ; Schinz, Syn. Mamm. vol. ii. 1845, p. 528.
Sciwroptera momoga, Blyth, Journ. As. Soc. Beng. vol. xxviii. 1859, p. 278.
This is a slightly larger species than P. volans, and differs from it id its dull
reddish-brown upper fur. The under parts are white, and the central line of
the tail above and below is dusky brownish-black. The tail is shorter than the body
and distichous. The ears are rather short, broad at the base and not tufted. Cheek-
bristles are absent.
Length of body . . . . . . . . . . . 7'08
tail . 4-07
Inhabits Japan.
1 The specific name of this squirrel is often erroneously written P . momoga instead of P . momonga.