Fig. 17. Gyrocotyle fimbriata. Diagram of the nervous system of the 

 posterior extremity. From Kofoid and Watson (1910, fig. 3). 



Fig. 18. Diagram of the arrangement of muscle-layers in the saggital 

 section. 



Fig. 19. Diagram showing track made by living specimen across 

 dish. Distance traversed, about 14 cm.; four contractions. 



Fig. 20. Sketch of network of excretory canals in the lateral fold 

 as seen in a living specimen. Zeiss-Greenough binocular. 



Fig. 21. Diagram, reproductive system, typical heterocotylean trema- 

 tode. (After Benham, 1891, p. 51.) 



cut. — cuticle. 



cut. trans. — cuticular transverse muscle. 



cut. long. — cuticular longitudinal muscles. 



clist. r. comm. — distal ring commissure. 



ex. can. — excretory canal. 



in. long. — inner longitudinal muscle. 



in. trans. — inner transverse muscle. 



lat. f. — lateral fold. 



lat. long. conn. — lateral longitudinal connective. 



marg. ex. sin. — marginal excretory sinus. 



med. long. conn. — median longitudinal connective. 



out. long. — outer longitudinal muscle. 



out. trans. — outer transverse muscle. 



post. or. comm. — posterior bridge commissure. 



subcutic. I. — subcuticular layer. 



rit. — vitellaria. 



v. op. — vaginal opening. 



[442] 



