72 MR. G. BUSK ON THE ANCIENT OR 
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particulars of these supposed species, since those contained in the short notices 
above cited are insufficient to allow us fairly to judge of the correctness or not of 
his determinations, and especially in a case in which we are required to accept the 
extraordinary discovery of four entirely new specific forms in such a limited loca- 
lity. And I am obliged to confess that, having been allowed, through M. Bour- 
guignat’s extreme kindness and liberality, to study his collection of Ursine remains 
from the Thaya cavern, they hardly appeared to me to present characters which 
I should have thought sufficient (considering the extreme variability of all Bears) 
to justify the distinctions he has set up. As an instance, I may mention that M. 
Bourguignat divides his four species into two groups, one of which, consisting of the 
two ancient forms U. lartetianus and U. rowvieri, is characterized by the presence of 
a perforation at the bottom of the olecranon-fossa, which he regards as a special 
character distinctive of certain African Urside, as contradistinguished from those with- 
out a perforation, which he considers to belong to a European type. Leaving on 
one side the evidence upon which M. Bourguignat may rest in attributing this or any 
other character to African Bears, I would merely remark that more extended ob- 
servation has perhaps since convinced him that such a character is of no value 
whatever, as it may occasionally be observed, certainly in U. speleus, and probably in 
all Bears, as it is also in Man and many other mammals. 
But as regards the Gibraltar Bear, it is matter of considerable interest to inquire 
whether it may not have an intimate relationship with one or other of these ancient 
Algerian forms. Probability is highly in favour of such a supposition. And the 
question then arises, What is or what are the known species to which M. Bourguignat’s 
Bears most closely assimilate ? 
Our means of judging with respect to this are at present very limited; but, to judge ~ 
from the lower dentition of U. faidherbianus (Odontogram 9 a, Pl. XXVIL.), there is 
nothing opposed to the supposition that it represents U. arctos, or a small form of the 
ferox type, from the comparative width of the fourth premolar, which is greater in 
U. fossilis and U. ferow than it usually is in U. arctos’. 
The only other of M. Bourguignat’s forms of which I have any data is U. letourneux- 
zanus, of which the maxillary dentition is shown in Odontogram No, 9, Pl. XX VIL; and 
from this it would seem to have been a Bear with teeth in size fully above the mean 
of U. speleus, and with a second upper molar much larger than in any U. fossilis or 
U. ferox that has come under my observation. The presence, however, of the first 
and third premolars shows that it did not belong to U. speleus. 
But one of the most interesting points connected with M. Bourguignat’s discovery 
of Ursine remains in the Algerian cavern is the establishment, beyond doubt, of the 
‘ In U. arctos I haye not as yet met with an instance in which the thickness of pm. 4 reached 0'"'3, it being 
usually 0'"25; whilst in U. ferow it is always at least 0-3 thick, and sometimes 0'"35, 
