716 



THE AMERICAN NATURALIST 



[Vol. XL 



through which the esophagus passes and into which some of the 

 retractors of the proboscis (to be dealt with later) are inserted (Fig. 

 2, rpb.). 



The proboscis is a hollow tube containing within it the esophagus- 

 and the large cylindrical mass, called the buccal mass. 



Nervous Ganglia. — The ganglia lie below the base of the pro- 

 boscis (in its protruded state) in the deep part of the head fold 



and surround the esophagus (Fig. 3, nq.) The - ii 

 the buccal, two small spherical ganglia closrlv i, 

 ventral surface of the esophagus and unitccl l)\ • 

 the two cerebral ganglia; the pleural uannliH- the c 

 pair; and the large pedal ganglia. Tlu>ir relations 

 in the accompanying diagrannnatic figure (Fig 4). 



J 



