PLATE 28. 



Figs. 1-6, 8, 9. Cross sections of Chac'todonua hawaiicnsis. X 55; Figs. 7, 10-12. Cli.ic'oMrrnia 

 nanula. X 33. 



Fip;. 1 . Through brain and buccal plate. 



Fig. 2. Through radula. 



Fig. 3. Througli junction of pharynx and stomach. 



Fig. 4. Tiirougli suprarectal commissure. 



Fig. 5. Through heart and coelonioiluct.s. 



Fig. 6. Tlirougli outlet of coelomoducf, on left, and origin of pericardial o])ening. 



P^ig. 7. Through brain region. 



Fig. 8. Through posterior end of prothorax. 



Fig. 9. Longitudinal section of posterior end. 



Fig. 10. Section through outlet of coelomoducf, on left. 



Fig. 11. Through radula. 



Fig. 12. Through suprarectal commissure. 



