28 Jdiirn.il (/t 1 iitdinology :ind Zoolog\- 



Explanation of Figures 



Fig. 1. Cemral ganglia of Myiiliis. The cerehral ganglia are above in the fig- 

 ure. X6. 



Fig. 2. Longitudinal section of the cerebral ganglion of Mylilus. The connec- 

 tive end is down. X70. 



Fig. 3. Cross section of the cerebral ganglion of Mytilus. The dorsal side 

 is up. X70. 



Fig. 4. Cross section of the pedal ganglion of \fvtilus. The dorsal side is up. 

 X70. 



