Castle. — Rhj-nchobdeUidsB. 



PLATE 1. 



Fig. 1. G. stagnalis. Entire digestive tract sliown ; somite limits indicated 1)}' 

 transverse lines, rings not represented. From an entire preparation. 

 X about 16. 



Fig. 2. G. parasitica. Parasagittal section of head end of a small individual taken 

 from a turtle (probably Chelopus insculptus Le Conte) bouglii in a 

 Philadelphia market. Only one (the largest) of the three closely asso- 

 ciated pairs of eyes appear in the section. 



Fig. 3. G. staijnalis. Ventral view of head end, showing mouth, oral sucker, and 

 the marginal sensill^ and annulation of somites i.-vi. From an entire 

 preparation. X 83. 



Fig. 3 a. G. parasitica. Dorsal view of brain. 



Fig. 3 b. G. parasitica. Ventral view of anterior part of a small individual obtained 

 from the same source as that shown in Figure 2. From an entire 

 preparation. 



