; 5 
one root; they are all which could be found in the specimen ex- 
amined ; and it is only by inspecting several individuals that the 
dental formula of this little animal could be correctly ascertained. 
It is supposed by the authors, that in front of the foremost pair of 
teeth of the upper jaw here described, another tooth exists, the root 
of which only is visible; if such should be the case, there would 
then be three pairs of incisors of unequal size in the upper jaw, and 
behind these a canine, which is the largest of those teeth. 
The Tarsipes, as has been shown, presents characters which could 
scarcely be supposed to exist in a single species, and affords an ad- 
ditional proof that the inspection of a single portion of any animal 
is not sufficient for the determination of the peculiarities of other 
parts. Its feet are those of an animal elevated in the scale of 
organization, and nearly resemble those of the Tarsius, differing 
only in the union of the second and third toes of the hind-feet. 
The Tarsipes also having these two toes shorter than the others and 
provided with subulated nails; the singular form of its teeth, and, 
above all, the analogy which its skull bears with that of the Mono- 
delph Edentata and Monotremata, render it difficult to determine 
the rank which the Tarsipes ought to occupy among the Syn- 
dactylous Marsupialia. It may be observed that it makes a con- 
siderable approach to Myrmecobius, an animal which, in some re- 
spects, has likewise affinities with the Hdentata; but here the feet 
nearly resemble those of the Dasyuri. The Tarsipes in all proba- 
bility had a long tongue, as in the Echidna and the Myrmecophaga ; 
and it appears, according to the observations made by Lieutenant 
Dale and Mr. Gilbert, and communicated to M. Gervais by Mr. . 
Waterhouse, that the tongue of the Myrmecobius is also very long. 
Mr. Gould exhibited a new species of Petrogale, which he charac- 
terized as follows :— 
PeTROGALE 1NoRNATA. Petr. facie et dorso arenaceo-cinereis ; 
humeris canescente irroratis, lateribus pallidioribus absque notis 
conspicuis ; antibrachiis tarsisque arenaceo-cinereis digitis ad api- 
cem saturate fuscis ; caudd dimidid basali arenaceo-fuscd. 
Hab. North coast of Australia. 
General colour of the upper parts sandy grey, grizzled over the 
shoulders, and becoming much lighter on the flanks; an indistinct 
line, of a lighter hue, along the face under the eye; a dusky red 
patch behind the elbow; under surface sandy white, inclining to 
rufous on the lower part of the abdomen; arms and tarsi sandy grey, 
passing into dark brown at the extreme tips of the toes; basal half 
of the tail sandy brown, the remainder black, the former colour ex- 
tending along the sides of the tail for some distance towards the tip ; 
ears sandy grey, bordered by a very narrow line of dark brown on 
their inner edge; a dark patch at the occiput, passing into a dark 
line down the forehead. 
