24 
9”) 
ad 
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
ParRKER. — Optic Chiasma. 
EXPLANATION OF THE PLATE. 
All figures represent dorsal views of brains of teleosts from which the cerebral 
hemispheres have been removed, thus exposing the optic nerves, chiasmata, and 
parts of the tracts. The optic lobes, cerebellum, and medulla are shown in each 
instance, as well as the outline of the eyeballs. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
1 
2. 
3. 
Gadus morrhua Linn. Left optic nerve dorsal. 
Gadus morrhua Linn. Right optic nerve dorsal. 
Lophopsetta maculata (Mitchill). Sinistral species. Right optic nerve 
dorsal. 
Pseudopleuronectes americanus (Walbaum). Dextral species. Left optic 
nerve dorsal. For the best exposure of the chiasma the brain is viewed 
from an antero dorsal position; hence the optic lobes are somewhat 
foreshortened. 
Paralichthys californicus (Ayres). Sinistral species. Sinistral individual. 
Right optic nerve dorsal. 
Paralichthys californicus (Ayres). Sinistral species. Dextral individual. 
Right optic nerve dorsal. 
Platichthys stellatus (Pallas). Dextral species. Sinistral individual. 
Left optic nerve dorsal. 
Platichthys stellatus (Pallas). Dextral species. Dextral individual. 
Left optic nerve dorsal. 
», 
