PLATE XXVIII. 



PAGE 



Figs. 1-11. Hyalonema diver gens, F. E. S., . . 199 



Fig. 1. Somewhat damaged specimen, preserved in alcohol ; natural size. 



Fig. 2. Marginal oxydiact with four central knobs ; x 100. 



Fig. 3. Great amphidise of the dermal membrane ; x 300. 



Figs. 4, 5. Smaller amphidiscs ; x 300. 



Fig. 6. Oxyhexact with smooth bent rays ; x 300. 



Fig. 7. Autodermal pentact pinulus ; x 100. 



Fig. 8. Oxyhexact with smooth straight rays ; x 300. 



Fig. 9. Oxyhexact with smooth bent rays ; x 300. 



Figs. 10, 11. Strong short spicules, triact and tetract, with rough ends, from the 

 basal pad of the body ; x 100. 



Figs. 12-17. Hyalonona lusitanicum, Bocage, . . 225 



Fig. 12. Small amphidise ; x 300. 



Fig. 13. Middle-sized amphidise ; x 300. 



Fig. 14. Greater amphidise with nodular axial beam ; x 300. 



Fig. 15. Oxyhexact with smooth bent rays ; x 300. 



Fig. 16. Oxyhexact with smooth straight rays; x 300. 



Fig. 17. Autodermal pentact pinulus ; x 300. 



