AMPHIBIA. 49 



PLATES XII. .XIII. 



THE BEAIN AND SPINAL CORD OF THE TURTLE. 



(TESTUDO MYDAS.) 



FIG. I. 

 DORSAL ASPECT. . 



THIS figure, and the first in the next plate, exhibit the summit of the brain and 

 the posterior surface of the spinal cord. 



a. Anterior lobes of the brain. 



b. Optic or posterior lobes of the brain. 



c. Cerebellum. 



In the spinal cord there are not any posterior bundles to join the anterior of the 

 two first cervical nerves. All the posterior bundles of the cervical nerves are seen 

 much smaller than the anterior, those of the thoracic larger, and those of the sacral 

 rather less. 



1. Olfactory nerve continued from the anterior point of the anterior lobe, and 

 passing to the nose, but not forming a ganglion, and terminating in coarse 

 brushes on the Schneiderian membrane. 



