182 MR. F, E, BEDDARD ON THE | Feb. 16, 
transverse section across the coil in the two former species the 
colon would be cut across eight times ; in the case of Cephalophus 
dorsalis ten times. The result is of course that the apex of the 
spiral is rather different in the two cases. Furthermore, while 
in C. melanorrhous and C. maxwelli the ileo-ceecal mesentery is 
inserted up to the very tip of the cecum, it falls considerably 
short of this in C. dorsalis. . 
Dr. Lonnberg* has used a very convenient method of ex- 
pressing the direction of the various loops of the colic spiral, 
which I adopt in comparing Anéilocapra with Cephalophus and 
some other forms (see text-fig. 13). The thick black line indicates 
the entering colon ; the pale line the colon which leaves the coil. 
The letter X indicates a fixed point in all the figures, 7. ¢., the 
extremity of the colic spiral, which is of course merely a single 
loop like that of Lemur, &c., and is wrapped within its own curves 
to form a spiral. It will be noticed that the simplest spiral 
exhibited among these Antelopes is that of J/adoqua which will 
be deseribed later. It forms a complete circle, each limb being 
approximately equal. The spiral of Cephalophus dorsalis is a 
further advance upon this; the spiral in this Antelope consists 
of two circles, each limb again being approximately equal. It 
will be noticed that in both these cases the limb of the spiral, 
which is continuous with the cecal side of the colon, ends on the 
same side of the spine as that on which the cecum lies, and, 
furthermore, that the number of the loops of the entering and 
outgoing colon are equal, 7. ¢., three of each in Madoqua and 
five of each in Cephalophus dorsalis. 
Tragulus stanleyanus, Cephalophus maxwelli, and Antilocapra 
form another and a parallel series of ascending complexity. The 
first-named is on the same level as Madoqua. The spiral has 
only one turn. But the arrangement of the loops is different. 
It happens that in Zragulus stanleyanus the end of the spiral 
is directed away from the cecal side of the spiral, z.e., trans- 
versely to the antero-posterior axis of the spiral and to the 
direction of the terminal loop in the other types already described. 
It will be seen, however, that if the spiral be increased by half 
a turn so that the axis of the end of the spiral be made to 
coincide with that of the other types, the limb of the terminal 
part of the spiral which lies on the cecal side of the spiral is not 
a part of the entering coil of intestine as in Madoqua and Cepha- 
lophus dorsalis, but of the outgoing coil. In Cephalophus 
maxwelli the spiral is more complex, 7. e. larger, but there is 
precisely the same relative position of the entering and outgoing 
limb of the spiral asin Zragulus. So finally in Antilocapra, which 
belongs to this same series. Here, however, the tip of the spiral 
is directed upwards; but if this be altered so as to make the 
spiral of the same length as in Cephalophus maawelli, it will be 
seen that the limb of the spiral which forms the cecal side of the 
* Zoologiska Studier tillagnade Prof. T. Tullberg. Uppsala, 1907, p. 248. 
