178 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
be well to mention a few suggestive facts brought out by a study 
of the skull of Scaphoceros. 
Since the accessory columns in the inner angles of the molar 
teeth are possessed by Ovibos (and probably by Scaphoceros) as 
well as Bos and Bison (see footnote, antea, p. 177) this character can 
only be used to separate these genera collectively from the sheep 
and related forms which never possess it. Without considering ex- 
ternal characters, Ovibos and Scaphoceros may then be distinguished 
from Bos and Bison and their relatives by the possession of lacrymal 
fosse, by the shape, direction, and manner of attachment of the 
horns, and by numerous less important characters. In some of 
these Scaphoceros shows more appproach to Bison than does Ovibos. 
Among them are the size and relative width of the teeth, the grooved 
basioccipital, and the more nearly round horns. These similarities, 
however, seem to be greatly overbalanced by the differences and do 
not necessarily indicate a bison-like ancestor for the musk ox. It 
seems more reasonable that Ovibos came from a more remote 
ancestor than Bison and developed along lines of its own. This has 
been ably set forth by Lonnberg (1. c.) and there appears to be 
nothing in the characters of Scaphoceros that would argue greatly 
against his views. 
In connection with any supposition that Scaphoceros may be an 
ancestral form of Ovibos, it is interesting to note that some characters 
of the adult Scaphoceros are found in the young Ovibos. In the 
young skull previously mentioned (see footnote, antea, p. 177) the 
basioccipital is very similar to that of the adult Scaphoceros, having 
a median depression and sides that are not parallel; also, the orbits 
are less produced laterally, the occipital condyles relatively wider, 
and the horn cores more divergent and less compressed, all of which 
approaches the condition of the adult in Scaphoceros. A still more 
primitive form is Boétherium bombifrons which, in the adult, has 
round horn cores, a condition only found in very immature Ovibos. 
History and Nomenclature-—Remains of animals related to or 
indistinguishable from the recent genus Ovibos have been found in 
Pleistocene gravels of various parts of the world. They were first 
found in Siberia near the Obi River and account of them was pub- 
lished by Pallas in 1773. Later, others from various parts of Siberia 
were unearthed and then more were found in the ‘ice cliffs’ of 
Eschscholtz Bay, Alaska. In course of time specimens came to 
light from the Mississippi Valley and from various parts of Europe, 
including England, Germany, and France. Such a large number 
of fragments naturally elicited a few new specific names, most of 
