178 PROF. W. H. FLOWER ON THE MUSK-DEER. |[Mar. 16, 
has been so long mounted in the Museum of the College of Surgeons 
there are certainly 14 ribs ; but in two others presented by Mr. Bryan 
Hodgson there are but 13, which is the number in the female subject 
of the present notice. It is curious that if Moschus sometimes varies 
in excess of the number of ribs usual to the Cervide, Hydropotes 
differs in the opposite direction ; for the fine skeleton of a male of 
that species lately presented to the Museum by Mr. Swinhoe has but 
12 pairs. 
Systematic Position and Affinities of Moschus. 
Although, in consequence of imperfect knowledge or imperfect 
reasoning upon such knowledge as we possess, a large portion of our 
present system of zoological classification can only be looked upon as 
tentative and provisional, there are certain conclusions which we have 
good reason to believe no future discoveries will ever change, and upon 
which we can therefore take our stand and say they are questions of 
fact and not of opinion. 
One such is that the Paridigitate Ungulates of Cuvier (the Ar- 
TropactyLa of Owen, the “ Bisulques” of Gervais) form a definite 
natural group, all the members of which are more nearly related to 
each other than they are to any other mammals. Of no large group 
do we know the past history so thoroughly ; and our knowledge of it 
has enabled us to fill up almost every important link since the middle 
of the Eocene epoch, and to show the gradual steps by which its 
different modifications have been brought about*. 
Another fact which I think indisputable is that, by the extinction 
of the various intermediate forms, four distinct modifications of the 
original Artiodactyle type have been left at present inhabiting the 
earth’s surface, which fre the Suina (including the Pigs and Hippo- 
potamus), the Tylopodat (the Camels and Llamas), the Tragulinat 
or Chevrotains, and the true Ruminants (called also Pecora and Co- 
tylophora). 
* Our present state of knowledge on this subject has been very ably and in- 
geniously expounded by Dr. W. Kowaleysky in his “ Monographie des genus 
Anthracotherium, Cuy., und Versuch einer natiirlichen Classification der fossilen 
Hufthiere,” Paleontographica, xxii. 1873, An abstract will be found in a paper 
by the same author ‘‘On the Osteology of the Hyopotamide,” Proc. Roy. Soe. 
yol, xxi, p. 147, 1873. 
See also W. H. Flower, ‘On Paleontological Evidence of Gradual Modifi- 
cations of Animal Forms,” Proceedings of the Royal Institution of Great 
Britain, April 25th, 1873. 
+ Iliger, ‘Prodromus, 1811. Phalangigrada and Digitigrada, proposed sub- 
sequently, have no advantage over the earlier name. 
+ The known members of this group, constituted of the genera Tragulus 
and Hyomoschus, are so closely allied as to form a single family, which, accord- 
ing to the most convenient rules of zoological nomenclature, would be called 
Tragulide; but I use the above termination as implying that they constitute 
a zoological division of more than family importance, equivalent, in fact, to the 
three others mentioned above. Although the French word Chevrotain and the 
Latin Tragulus may have had originally nothing to do with these animals, it is 
very desirable, in default of any better designation, to keep them for their ex- 
clusive use, and never for the future to allow such unfortunate expressions as 
““Pigmy Musk-Deer” to remain to convey false notions of zoologicai affinities. 
