S108) ANATOMY OF CERTAIN UNGULATA. 197 
and floating in the abdominal cavity, the homology of which 
is doubtful. (See p. 168.) 
(6) The posterior region of the csophagus in Sus (Porcula) 
salvania is covered by a sheet of muscle which arises as a 
stout muscular slip from the vertebral column from the 
centrum of the 8th or a closely neighbouring vertebra. 
This muscle has not been met with in other mammals, but 
may correspond to minute fascicles which in man bind down 
the esophagus to adjacent membranes massed into one large 
muscle. (See p. 170.) 
(7) The musculature of Antilocapra americana shows certain 
differences from that of other Bovines in the extensors and 
flexors of the arm and leg. (See p. 175.) 
(8) The colic helicines of Antilocapra, Cephalophus, Madoqua, 
Moschus, Gazella, and Tragulus are shown to be referable to 
two categories according to whether the emergent spiral 
limb of the colon lies to the right or to the left of the 
entering spiral. Even the two simplest spirals known among 
Artiodactyles, i.e. those of Madoqua and Tragulus, conform 
to the one or to the other plan. (See p. 182.) 
(9) Although two species alleged to be of the same genus, viz. 
Cephalophus dorsalis and C. maawwelli, show different spirals, 
it is by no means certain that these two species are rightly 
referred to one and the same genus. (See p. 181.) 
(10) In no Artiodactyle (whose anatomy is known) is the common 
form, from which the two types may have diverged, of spiral 
visible. But the rudimentary spiral of the Galagine and 
Lorisinze (among Lemurs) is a spiral from which both types 
of Artiodactyle spiral might be derived. (See p. 185.) 
(11) The remarkable spiral of the Musk-Ox, described by 
Lénnberg, in which the emergent limb is bent once upon 
itself before leaving the region of the spiral, is closely 
paralleled in one specimen (out of two) of the Rodent 
Dasyprocta punctata, (See p. 187.) 
(12) The azygos vein of Madoqua is like that of Rhaphicerus and 
Ourebia in that the left azygos has an anteriorly running 
branch as well as the chief posteriorly running trunk. These 
genera are usually placed in the same subfamily—Neotragine. 
(See p. 188.) 
(13) In the brain of Madogqua, as in that of other small 
Ruminants, the splenial sulcus is exposed and superficial in 
position. (See p. 190.) 
(14) The brain of Babyrussa is like that of other Old World 
Suide. Its slight divergences are not in the direction of 
the New World Dicotyles. (See p. 192.) 
(15) The brain of Antilocapra is remarkable for its squared-off 
ending anteriorly and for the fact that, as in the Suide, the 
crucial and coronal sulci are confluent. (See p. 173.) 
