294 s. GOTO. 



Plate XX. 



Phyllonella hippoglossi. 

 Fig. 1. Anterior end of the body, x about 5. 

 ,, 2. Cross-section through the anterior part of the body, x about 20. 

 „ 3. Genital organs, with the exception of the vitellarium. x 18. 

 „ 4. Chitinous hooks of the posterior sucker, a anterior piece, b middle 



piece, e posterior piece, d chitinous granules. (Zeiss 2AA.) 

 „ 5. Gigantic cells in the vicinity of the chitinous hooks of the posterior 



sucker. Zeiss 3 A. 

 ,, 6. Portion of a cross-section through the posterior sucker; to show the 



relation of the gigantic cells to the surrounding tissues, x 250. 

 „ 7. Ganglion cells of the posterior sucker and nerve plexus. Zeiss 1 D. 



Epibdel/a sciaenae. 

 „ 8. The whole animal in the ventral aspect ; from a specimen in possession 



of Dr. Stiles of AVashington. x 7. 

 „ 9. Chitinous hooks of the posterior sucker. The hooks are not in their 



natural relative position. X 190. 



Trlsfomum levé. 

 „ 10. Chitinous corpuscles on the surface of 2V. hisiiophori Bell, x 250. 

 ,, 11. Chitinous hook from the posterior sucker of Tr. levé Verrill, x 54. 

 ,, 12. Chitinous hook from the posterior sucker of T/'. histiojyJiorl BeW. x 54. 



Hexacotyle thimninœ. 

 „ 13. The entire animal, from a specimen in possession of Dr. Stiles of 



Washington. There was an injury in the hind part of the body. 

 ,, 14. Chitinous armature of the posterior suckers, a the piece at the inner end, 



b the one in the middle, e the one at the outer end. 

 „ 15. Chitinous hooks at the posterior end of the body, a inner hook, b outer 



liook. X 270. 



Plate XXI. 

 Polystomuyn Ha-'^salll n. sp. 

 ,, Iß. The entire animal in the ventral aspect, x 61. 



,, 17. a larger hook at the posterior end of the adhesive disc, b hook in the 

 posterior suckers, x 190. 



Polystomum oblongum of Leidy. 

 „ 18. Penis hook, x 200. 



Dionehus Agassizi n. g. n. sp. 

 „ 19. The entire animal in the ventral aspect, x 54. 

 „ 20. Ventral view of the posterior sucker. 

 „ 21. Two views of the posterior hooks, x 250. 



