RODENTIA.
SCIURIDiE.
Genus S c i t j r t j s , Linn.
In identifying the squirrels collected on the two Expeditions to Western China,
I was led to examine the whole group of the south-eastern Asiatic species of the
genus Scmrus, and the results are here recorded.
That remarkable Malayan and Bornean form, with the long snout, which has
been elevated by Dr. Gray to a separate genus under the term Bhmoscmrus, I have
made the subject^ of a few observations at the end of this Memoir. I t seems to me
that its structural features are not so much differentiated from the ordinary squirrels
as to warrant its being apportioned more than sub-generic rank, and if the other
squirrel, also from Borneo, which Dr. Gray first described as Scwrw macrotis and
afterwards raised to generic rank as Bheithroscmrus, does not present any other
modifications on the ordinary Scmrme type beyond the longitudinal grooving of the
incisors, its ms to more than sub-generic distinctness would seem to be doubtful.
With regard to the genus Seiurus itself, it forms a natural and well-defined
group, containing a large assemblage of forms which differ in details of merely
specific value. With the two exceptions just mentioned, I fail to detect any
characters to favour the view, that variation in dentition, or in the tufting of their
ears, occurs to a degree sufficient to entitle them to be separated into sub-genera.
The dentition and the form of the skull throughout the group rather present a
remarkable uniformity. The tufting of the ears is apparently not a seasonal or
climatic circumstance, such as that to which the common squirrel of Europe is
well known to be subject. Certain modifications in the external appearance of the
g.nima.ls are doubtless produced by the stage of their growth; the pelage of some,
in whole or in part, becoming darker or lighter, as they pass from youth to maturity,
and occasionally there is a complete change of colour. The young of S. rafflesii,
for example, I have frequently observed to be bom with a pure white tail which
gradually changes to black in the adult, showing a slight tendency to rufous tipping;
apparently also S. ferrugvneus has annulated hair in youth which becomes brilliant
red at maturity. But the diversity in the physical conditions of the countries which
the squirrels inhabit, and the nature and relative abundance of their food, exercise a
most potent influence on their organisms, leading to variations in size, form, and
intensity of colour. The species S. maclellmdi affords a good illustration of this. I t
ranges over a wide geographical area, and when a series of individuals are brought
together from the Himalaya, the Malayan peninsula, Eormosa, Central China, and
Tibet, however divergent those from the extreme limits of distribution may appear,
the races from the intermediate localities show a connecting, gradational series. But
besides these, there are evidently other and occult causes at work producing local
modifications in the pelage of certain species and which are the occasion of much
perplexity to the systematist. This is especially observable in such squirrels as
S. pygerythrus, S.phayrei, S. blanfordii, S. camceps, and S.ferrugmeus.
In the following pages it has been attempted to indicate the transitional phases,
varieties, or local races, whichever they may ultimately prove to be, that appear
referable to given species, but the following interpretation of the similarities which
some of them manifest to certain species may not be considered as conclusive
evidence of their identity, yet the facts generally would seem to prove that the course
followed is one in the right direction.
S c it j r t j s b i c o l o r , Sparrmwm.
The Javan Squirrel, Pennant, Hist. Quad. 1798, 3rd ed. p. 142.
Seiurus bicolor, Sparr. Gotheb. Wet. Sevensk. Handl. vol. i. 1778, p. 70; Pallas, Hist. Nat. Quad.
Glir. 1778, p. 877 ; Gmelin, Syst. Nat. 18th ed. vol. i. 1788, p. 148 ; Pennant, Hist. Quad.
3rd ed. 1798, p. 142; Shaw, Genl. Zool. vol. ii. pi. i. 1801, p. 180 ; Desmarest, Nouv. Diet.
d'Hist. Nat. vol. x. 1817, p. 105; Märiiin. 1820, p. 886, pi. lxxv. fig. 8 (Schreber's figure
of S. javensis) ; Kuhl. Beitr. Zur. Zool. und Anat. 1820, p. 68 ; Horsfield's Zool. Resch. Java,
1824,plate; Proe. Zool. -Soc. 1839, p. 150; Cat. Mamm. E. Ind. Co.’s Mus. 1851, p. 155
(in part) ; Desmoulins, Diet. Class. d'Hist. Nat. vol. vi. 1842, p. 72; Lesson, Man. de Zool.
1827, p. 286; Fischer, Syn. Quad. 1829, p. 857 (in part) ; Wagner, Schreber, Säugeth. Suppl.
• vol. iii. 1848, p. 189 (in part), plate ccxvi. A; Müller und Schlegel, Verhandl. 1839-44, pp. 85,
88 (in part); Schinz, Syn. Mamm. vol. ii. 1845, p. 32 (in part) ; Blyth, Cat. Mamm. As. Soc.
Mus. 1868, p. 99 (in part).
Seiurus javensis, Zimmermann, Geograph. Gesch. 1780, vol. ii. p. 842; Schreber, Säugeth. vol. iv.
1792, p. 781, pi. 216; Gray, Hand-List Mamm. B. M. 1848, p. 186; Proc. Zool. Soc. 1861,
p. 187 ; Blyth, Journ. As. Soc. Bengal, vol. xvi. 1847, p. 870.
Seiurus albiceps, Desmarest, Noûv. Diet. d'Hist. Nat. vol. x. 1817, p. 105 ; Desmoulins, Diet. Class.
d'Hist. Nat. vol. vi. 1824, p. 72; Gray, Griffith's An. Kingd. vol. iii. 1827, plate opposite to
p. 180.
Seiurus leschenaultii,Desmarest,Ma,mm. 1820, p. 835; Horsfield, Zool. Resch. Java; Gray, Griffith's
An. Kingd. vol. iii. 1827, p. 180, (plate S. albiceps)', Lesson, Man. de Zool. 1827, p. 236;
Fischer, Syn. Mamm. 1829, p. 856 ; Schinz, Syn. Mamm. vol. ii. 1845, p. 88.
Seiurus affinis, Raffles (nec Horsfd.) Trans. Linn. Soc. vol. xiii. 1822, p. 259 ; Lesson, Man. de
Zool. 1827, p. 234; Fischer, Syn. Mamm. 1829, p. 855 (in part) ; Wagner, Schreber, Säugeth.
Süppl. vol. iii. 1848, p. 202 ; Schinz, Syn. Mamm. vol. ii. 1845 (in part), p. 44 ; Blyth,
Ann. and Mag. Nat. Hist. vol. xx. 1847, p. 814.
Seiurus hypoleucus, Horsfield, Zool. Resch. Java, 1824; Cat. Mamm. E. Ind. Co.'s Mus: 1851,
p. 156; Müller und Schlegel, Verhandl. 1889-44, pp. 85, 90; Gray, Hand-List Mamm.
B. M. 1843, p. 187; Wagner, Schreber, Säugeth. Suppl. vol. iii. 1843, p. 189; Blyth, Journ.
As. Soc. Beng. vol. xvi. 1847, p. 870 ; Cat. Mamm. As. Soc. Mus. 1863, p. 99.
Seiurus auriventer, Is. Geoff. St.-Hil. Mag. de Zool. 1832, cl. i. pi. v. ; Voy. des Ind. Orient. Bélanger,
Zool. 1884, p. 150 ; Coulon, Mém. de la Soc. des. Sc. Nat. de Neufchat. vol. i. 1835, p.
128, pl. ix. ; Gervais, Eyd, et Soul. Voy. autour du Monde, Zöol. vol. i. 1841, p. 41 ; Mag. de