672 The American Naturalist. [August, — 
resentation and description, to which reference should be made 
in reading the following account: . 
In front of the pituitary space the trabecule unite into a 
broad horizontal plate, the line of junction of the two halves 
being entirely obsolete, while still farther forward the cornua 
trabecule, instead of being two-lobed, form a broad triangular 
plate. Between the two cornua isa deep and narrow notch 
with parallel sides in which is imbedded the septum osseum 
of the premaxilla to be described below. The trabeculae, on 
either side of the pituitary space, are high and compressed. 
Just behind the nasal capsules two processes are given off on 
either side. The upper one, arising from the trabecular crest 
is, as Hay calls it, the rudimentary nasal capsule, and in one 
specimen upon one side I found a perforation in this process 
which suggests the more extensive fenestration in the nasal 
cartilage of the adult Necturus and Protopterus. The lower 
process may retain the name, antorbital, usually applied to it, 
for Amphiuma presents no evidence that it is the palatine car- 
tilage as Gaupp interprets it. 
Somewhat farther behind these processes than in Hay’s 
figure are two openings through the trabecule for the passage 
of the optic and oculomotorius' nerves. 
The trabecule are united to the posterior portion of the car- 
tilaginous skull by three processes. The upper connects the — 
crista trabecule with the ear capsule; the middle, the process — 
ascendens of Stohr and other authors, goes from the trabec- 
ule to the inner anterior angle of the quadrate; the third, the 
radix trabecule, is bifurcate posteriorly, the outer ramus join- 
ing the floor of the otic capsule, the other uniting with the 
parachordal floor of the cranial cavity. 
The parachordal cartilage lies beneath the notochord, as 
do the lower ares of the occipital and first cervical vertebra. 
Between the parachordals and the otic capsule on either side 
is a large oval opening in the cranial floor. The occipital ver- 
tebra is confluent below with the parachordal cartilage; on 
_ Hay suspected that the posterior of these foramina was for the transmission of — 
the third nerve. I have traced the nerve from its origin, through the opening, into the - 
proper eye muscles. 
