15 {14) Pharynx long, tube-shaped, thick, and muscular; mouth opening subterminal at anterior end (Fig. 23) 

 Genus Hofstenia. 



Figure 23. — Hofstenia atroviridis. 



15 (14) Pharynx with only weakly muscular walls, either tube-shaped or short and globular; mouth opening ventral 

 near anterior end 



16 



16 (15) Pharynx long (about one- fourth body length), thin and tube-shaped (Fig. 24a); seminal vesicle enclosed in a 

 thick muscular wall which encloses also the cuticular elements of the penis (Fig. 24b). One species from the 

 Mediterranean Genus Hofsteniola. 



Figure 24. — Hofsteniola pardii. 



16 (15) Pharynx short (about one-sixth body length), thin-walled and globular (Fig. 25'a); seminal vesicle clearly 



separated from the bulb of the penis by a constriction (Fig. 25b). One species from .Brazil 



Genus Marcusio/a. 



Figure 25. — Marcusiola tinga. 



15 



