432 WILLIAM A. HILTON 



In Estheria it was very difficult to remove the ganglia intact, 

 so the sketch given is from the nervous system in situ for the 

 most part. The brain is of quite a different shape, the optic 

 ganglia are shown in the drawing connected with the compound 

 eyes, which nearly touch each other. Only one pair of antennal 

 nerves is shown in the drawing. The brain is more decidedly 



Fig. 4 Diagrammatic plan of cell arrangement in the ventral ganglia of 

 Branchipus. X 75. 



