4 
Dr. J. E. Gray on a new Species of Cuscus. 67 
observed the extreme differences which exist in their habits, food, 
note, &e. 
Judging from analogy, it is fair to believe that many of the spe- 
cies, even among the larger and best-known vertebrated animals, 
which are now considered doubtful, and sometimes only regarded 
as slight varieties, if properly observed and described, would prove 
to be quite distinct ; and if this be the case with the larger animals, 
what must it be with the smaller articulated and molluscous or radi- 
ated animals, which are very rarely described, except from_ specimens 
in one condition, often indeed from some isolated part of the ani- 
mal, as its shell or coral, as it is found in a museum? I cannot but 
think that until we have better materials to work from, it is rather 
rash to theorize on so important a question as the stability or muta- 
bility of species. 
As regards the animal now before us, instead of knowing its history 
in all its states, and having a full account of its habits and manners 
(and I cannot conceive that any species is well established without 
all these particulars), we have only a skin with its separated skull, 
and that of one sex, of a genus in which the sexes sometimes differ 
greatly in external appearance, and of which the species are very 
imperfectly known. 
Thus, for example, the section of the genus to which this specimen 
is referable contains at present two species,—one long known, and of 
which perhaps there are not more than twenty-five or thirty speci- 
mens in all the museums in Europe. The males in all these cases 
are pure white, and the females reddish with a narrow dorsal streak. 
Last year I described a second species from a male, a female, and a 
young specimen in the British Museum, in which both sexes are 
ashy-grey without any dorsal streaks, and which has not been observed 
in any other collection. Now I have described a third from a single 
adult male, which is bright reddish-yellow varied with white spots, 
having a very distinct narrow dorsal stripe. I have every reason to 
believe that this is a good and distinct species, but without stronger 
evidence I can hardly say that it is so, particularly as I have no 
knowledge of the female. Moreover, all the males of the species 
most nearly allied to it in the different museums are pure white, a 
eclour which is very rare in the animal kingdom, except when it 
arises from a state of albinism; and the eyes of this animal are 
represented in the published figures as red, as if it were an albino; 
and this male specimen has a distinct dorsal streak, which is the 
character that distinguishes the female of C. orientalis from the other 
species of the genus. I am therefore induced to inquire, can the 
males which we have hitherto had have been albinos? and is this 
the naturally-coloured male of that species? And though I ask the 
question in order to induce other naturalists further to examine the 
subject, I am myself inclined to regard C. ornatus as a distinct species. 
Whether this be the case or not, I do not think that this specimen 
affords any ground for believing that the three species of the genus 
were derived from a common origin, and have gradually separated 
themselves from each other, more especially as they all seem to be 
5* 
