296 EDWARD PHELPS ALLIS, JR. 
The arteria carotis interna of the rabbit is said by Voit to run 
upward through the foramen caroticum into the cavum epip- 
tericum, which, as explained above, is certainly incorrect. The 
artery is said then to run forward dorsal to the processus alaris 
of the ala temporalis, which is in accord with my interpretation 
of the conditions, for that process forms part of the floor of the 
dorsal myodomic cavity. The artery is said by Voit to lie lat- 
eral to a cartilage ‘c,’ which Voit considers to form part of the 
lateral wall of the cavum cerebrale cranii. This cartilage is, 
however, certainly a chondrification of a membrane shown, in 
one of Arai’s figures of this animal (’07, fig. 6, p. 482), running 
upward between the hypophysis mesially and the arteria caro- 
tis interna and the pituitary vein (so-called sinus cavernosus) 
laterally. This membrane is continued mesially between the 
hypophysis and the dorsal surface of the sella turcica, and is 
shown as a single membrane, but it must necessarily be formed 
by the fusion of two membranes, one forming the floor and the 
other the roof of the subpituitary myodomic cavity. The carti- 
lage ‘c’ is evidently a chondrification of some part of this mem- 
brane, and may therefore represent a chondrification of either 
one of its two components; and its position and its coalescence 
with the floor of the sella turcica seem to indicate that its basal 
portion belongs to both membranes while its dorsal portion be- 
longs to the dorsal membrane only and forms part of the roof 
of the myodomic cavity and hence of the wall of the cavum cere- 
brale cranii. The internal carotid accordingly here lies in a 
lateral portion of the myodomic cavity which has been sepa- 
rated from the median portion of the cavity by this wall of car- 
tilage. The cartilages ‘a’ and ‘b’ of Voit are, as he concluded, 
remnants of the mesial wall of the cavum epiptericum (tri- 
geminus recess). 
Because of the passage of the internal carotid through what 
Voit considered to be a part of the cavum epiptericum, he con- 
cludes (’09, p. 551) that this artery of the rabbit, and hence also 
that of others of the Mammalia ditremata, must run upward 
lateral to the trabecula, the internal carotid of these animals 
thus not being the homologue of the similarly named artery of 
