Plate XXIV. 



Teistomum ovale. 



Fig. 1. A small portion of the wall of the penis in longitudinal section, x 2C4 

 diam. 



„ 2. A small ventral portion of a cross-section of the body. x204. The 

 reference lines for I. mus. and diay. miis. should reach more inward, the 

 latter to the oblique lines next the cir. mus., and the former to the nume- 

 rous closely crowded dots next the foregoing. 



„ 3. Cross-section of the left anterior eye and its vicinity, x 427 diam. 



„ 4. Cross-section of the left posterior eye. x 427 diam. 



„ 5. Two nerve-cells from the brain, x 427 diam. 



Teistomum eotundum. 



Fig. 6. The whole worm viewed from the ventral side. On the right side the 

 testes are shown only in outline, and the vitellarium is wholly omitted. 

 „ 7. Three chitinous corpuscles from the margin of the body, x 204 diam. 

 „ 8. One of the hooks of the posterior sucker, x 204 diam. 

 „ 9. Central part of the genital organs viewed from the ventral side, x 29 

 diam. 



Teistomum foliaceum." 



Fig. 10. The whole worm viewed from the ventral side. The vitellarium is not 

 shown on the right side. 

 „ 11. Hooks of the posterior sucker, x 204 diam. 

 „ 12. Median sagittal section of the anterior part of the body, x 73 diam. 



