Coe and KRunkel— California Limbless Lizard. 387 
The olfactory lobes (pl. x11, figs. 1, 2, 3, o/f) are of regular 
ovoid shape, about twice as long as broad. The olfactory nerves 
come off from the anterior end in a ring of a diameter about one 
half that of the lobes. The lobes are closely applied to each other 
in the middle line except at the extreme anterior end, where they 
taper more abruptly. 
The cerebral hemispheres (c.4) are very large and very much 
elongated. hese are also ovoid in form with the greatest diameter 
at the posterior end. The cerebral hemispheres are differentiated 
from the olfactory lobes by a marked constriction which, however, 
allows of a rather wide connection between the two. 
The thalamencephalon is very small and is almost completely con- 
cealed by the neighboring parts of the brain. The pineal body is 
more or less pear-shaped and lies with its broad end directed posteri- 
orly and dorsally between the posterior ends of the cerebral hemi- 
spheres. A mass of blood vessels forming the choroid plexus of the 
third ventricle overlies the structure and is enclosed in the same 
mass of connective tissue with the epiphysis, so that superficially 
only a single structure is seen, On the ventral side of the thalam- 
encephalon is a well developed infundibulum (¢7) with the pituitary 
body attached distally. The anterior portion of the infundibulum is 
marked by four or five longitudinal folds which produce a corre- 
sponding number of scallops on the anterior end between two rather 
prominent ridges with rounded anterior ends, from which the optic 
nerves proceed. These lateral ridges continue into the ventral sides 
of the optic lobes. The infundibulum is of a regular conical form 
with an axis somewhat shorter than the diameter of the base. The 
apex of the cone is marked by a slight depression with a longitudi- 
nal slit at the bottom of the cup marking the attachment of the 
pituitary body. The pituitary body is not represented in the figures. 
The optic lobes (0.7) are rather small and placed very close 
together in the middle line, the two forming a more or less hemi- 
spherical mass. From the exterior their paired nature is only slightly 
indicated. Apparently this compression is due to the great develop- 
ment of the internal ears, which lie slightly posterior and dorsal to 
this part of the brain and approach each other very closely on the 
dorsal side. 
The cerebellum (¢.5) is very small and has the form of a transverse 
ridge lying posterior to the optic lobes, somewhat shorter than the 
diameter of this portion of the brain, and overhanging the anterior 
portion of the fourth ventricle. The medulla (md) is large and is 
