Plate VIII. 

 Myriotrochin^. 



Figures 1-G. Acanthotrochus mirabilis Dan. and Kor. (From Dan. and Kor., 1882.) 



Figure 1. Adult. Natural size. 



2. Adult. X 5 ( ?) 



3. Tentacle. X 100 (?) 



4. Small wheel. X 300 (?) 



5. Large wheel. X 185 ( ?) 



6. Calcareous ring, anterior view. X -^5 ( ?) 



Figures 7-14. Trochoderma elegans Theel. (From Theel, 1877.) 



Figure 7. Adult. Natural size. 



S. Tentacle, with calcareous ring, positional organs, and radial nerve. X 100 ( ?) 

 Figures 9-12. Successive stages in development of wheel. X 300 ( ?) 

 Figure 13. Wheel, seen from the side. X 425 ( ?) 

 14. Calcareous ring, side view. X 35 ( ?) 



Figures 15-30. Myrioirochus vitreus (M. Sars.). (From Kor. and Dan., 1877.) 



Figure 15. Adult, partly contracted. Slightly enlarged. 



16. Adult, fully extended. Slightly enlarged. 

 Figures 17-19. Wheels. X 140 ( ?) 

 Figure 20. Calcareous ring from dorsal side. X 3 ( ?) 



Figures 21-22. Myrioirochus rinkii Steenstrup. (From Dan. and Kor., 1882.) 



Figure 21. Adult, extended. Natural size. 



23. Wheel in normal position in skin. X 175 ( ?) 



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