1870. | PROF. W. H. FLOWER ON ALURUS FULGENS. 76 
“MI 
CONCLUSION. 
With reference to the skeleton, I must content myself on the pre- 
sent occasion with noting that the vertebral formula is C. 7, D. 14, 
L. 6, 8. 3, C. 18*, that there is no trace of a clavicle, and that the 
humerus has a supracondylar perforation. 
It will be seen from the foregoing notes that, in all essential points 
of its structure, 4/urus conforms to the other arctoid or bear-like 
carnivora, a group comprising the Urside, Procyonide, and the Mus- 
telida. The question remains whether it can be included in either of 
those three families, or whether it must constitute a family for itself. 
In the structure of the viscera, the minor modifications from the 
general type characteristic of the section have not yet been studied 
with sufficient attention, or ina sufficient series of species, to be made 
use of in dividing the families or genera. This, however, is a subject 
to which the attention of systematic zoologists will naturally be more 
closely directed when the consideration of the external and more easily 
accessible characters becomes exhausted, or fails to supply the re- 
quired information. 
In the mean time, the dental characters, and more especially the 
number and form of the true molars, are generally relied on as, at 
all events, the most convenient for diagnosis. All the known 
Urside have 2 of these teeth on each side, all the known Procyo- 
nide 2, and all the known Mustelide 4, or in one case but 1, 
The Urside are characterized by the greatest development of the 
molar series backwards ; for not only is there an additional molar in 
the lower jaw, wanting in all the other forms, but the posterior molar 
in the upper jaw is a very large tooth ; and in all the most typical, 
or, rather, most specialized, Bears (Ursus proper) it is actually longer 
from before backwards than the tooth in front of it. In Melursus, 
and the section of Ursus called Helarctos, this tooth is scarcely, if at 
all, longer than the one in front of it; and the same is the case in the 
very generalized extinct Hyenarctos. In the Procyonide, on the 
other hand, it is always smaller than the tooth in front of it, thus 
indicating a transition to the condition of total absence met with in 
all the Mustelide. 
The existing Urside also differ, not only from the Procyonide, 
but from all other Carnivora, in the structure of the last upper pre- 
molar, or “‘sectorial tooth”? of the more typical members of the 
order. ‘This tooth usually consists essentially of a more or less 
compressed and cuspidated ‘‘ blade”’ supported on two roots, and an 
inner lobe (almost always near the anterior end of the blade) sup- 
ported by a distinct root. In the Urside alone the third root is 
wanting, and the inner lobe is either absent or quite at the posterior 
end of the blade, supported on a thickening of the posterior root +. 
* Hodgson gives thirteen dorsal and five lumbar vertebri, but states that he 
had not a perfect skeleton by him to refer to while writing. 
t In a specimen of Melursus labiatus in the Museum of the Royal College 
of Surgeons there is a small third root on the inner side of the last upper pre- 
molar, but this is confined to the tooth of one side of the jaw only. 
