CENTRAL NERVOUS SYSTEM IN VERTEBRATE ANIMALS. 
705 
r.c. 
r.i. 
r. l. 
s. c/.c. 
•s'. 
s. r. 
t. c.op. 
th. 
t.i. 
t.tri. 
t.v. 
v.cbl. 
v.h. 
v.h.g. 
v.l.c. 
v.op.l. 
v.r. 
v.th. 
v.v. 
Restiform column. 
Ramus intestinalis. 
Ramus lateralis. 
Substantia gelatinosa centralis. 
Superior maxilliary nerve. 
Sinus rhomboidalis or fourth ventricle. 
Tranverse commissure of the optic lobe. 
Thalamencephalon. 
Tuberculum intermedium, Gottsche. 
Tuberosity of the trifacial. 
Tuberosity of the vagus. 
Ventricle of the cerebellum. 
Ventricle of the liypoarium. 
Ventral horn of grey substance. 
Ventral longitudinal column. 
Ventricle of the optic lobe. 
Ventral root of the spinal nerve. 
Third ventricle. 
Valve of Vieussens, valvula cerebelli, or anterior medullary velum. 
PLATE 38. 
Fig. 1. Dorsal view of the brain of ScyIlium Catulus, the pia mater covering of 
the third and fourth ventricle removed. Natural size. 
Fig. 2. Dorsal view of the brain of Rhina Squatina, showing part of the distribution 
of the cranial nerves. Pia mater not removed. Natural size. 
Fig. 3. Dorsal view of the brain of Acanthias vulgaris. Pia mater not removed. 
Natural size. 
Fig. 4. Side view of the brain of Acanthias vulgaris. Natural size. 
Fig. 5. Dorsal view of the fourth ventricle and the optic lobes. Pia mater and 
cerebellum removed. X 2. 
Fig. 6. Transverse section through the spinal cord of Rhina Squatina. X 22. 
Fig. 7. Transverse section through the spinal cord of Rhina a little more in advance. 
X 22 
Fig. 8. Transverse section through the spinal cord immediately behind the fourth 
ventricle. Rhina X 22. 
Fig. 9. Transverse section through the posterior end of the Medulla oblongata. 
Rhina. X 22. 
Fig. 10. Transverse section through the middle of the fourth ventricle. Rhina. X 22. 
