398 _DR.W. PETERS ON PLATACANTHOMYS Lasiurus. [Apr. 25, 
PratacantTuomys, Blyth. 
Habitus myoxinus. Rostrum acutum, rhinario nudo, labro fisso ; 
oculi mediocres ; auricule mediocres nude ; vellus molle, setis 
dorsalibus latis sulcatis; artus mediocres, palme planteque 
pentadactyle, digito primo abbreviato, faleulis modicis curva- 
tis, acutis ; cauda villosa, versus apicem fere disticha. Dentes 
. . . . 3 . . 
primores leves, compressi, acuti, molares utrinque -, complicati. 
Cranium murinum, sed foraminibus incisivis parvis, coarctatis, 
ossibus intermazillaribus inclusis, palato perforato et processu 
coronoideo brevissimo. Ossa antibrachii sejuncta, cruris con- 
nata. 
The resemblance of this genus to the Dormouse, at first sight, 
is very striking, principally on account of the long-haired tail. But 
in other respects, in its smaller eyes, very thin ears, and the well- 
developed, although very short, thumb of the fore foot, it more ap- 
proaches several Murine genera of Tropical India. 
The skull is rather broad and flattened behind ; but it is quite 
impossible for any one who knows anything about the craniological 
characters of the Rodentia not to recognize at the first sight the 
typical form of the Murine, in the two-rooted zygomatic process of 
the upper jaw, together with the peculiar form of the foramen infra- 
orbitale, which is very high, narrowed, and widened above, and in 
the development of supra-orbital ridges, which form together a lyri- 
form figure. As peculiar and deviating from the typical skull of 
the Murine, are before all to be noted the small and narrow fora- 
mina incisiva, formed only by the intermaxillary bones, the imper- 
fect perforate palate, and the very short coronoid process of the 
lower jaw. 
The incisors are narrow, compressed, and pointed. The molar 
series are distant from and parallel to each other. The first and 
second upper molars are nearly of the same size, and much larger 
than the third and last. All three are composed of five enamel- 
folds or lamine, obliquely directed inwards and hindwards : the first 
and second of these are united as well on their inner as on their outer 
side; the third, fourth, and fifth are united on the inner side; but 
on the outer side only the first and fifth enamel-folds are united. 
The lower molars are of the same size as the corresponding upper 
ones ; but their enamel-folds are all united on the inner, and sepa- 
rate on the outer side, except in the first (which has six enamel- 
folds) the three anterior ones, and in the second and third (which 
have four enamel-folds) the first and second ones. 
PLATACANTHOMYS LAsturRus, Blyth. (Pl. XX.) 
P. magnitudine Muris ratti, auriculis acuminatis, capitis dimidio 
longioribus, vibrissis longissimis ; supra umbrino-fuscus, subtus 
albidus, jugulo pectoreque flavescentibus, cauda umbrino-fusca, 
apice albido. 
Long. a rostri apice ad caudze basin 0138; caude 0™110. 
Hab. India orientalis, prov. Malabar. 
