PLATE XL 



Figs. 1 -6 . — Agla ophen ia Jilicula. 



Fig. 1. — Natural size. 



Fig. 2. — Portion of hydrocladium, magnified ; lateral view. 



Fig. 3.- — Same ; front view. 



Fig. 4. — Corbula, closed form. 



Fig. 5.^ — Corbida, open form. 



Fig. 6. — One of the costse of the open form of corbida, showing the slit-like orifice nea? 

 its base. 



Figs. 7-9. — Aglaophenia attemuxta. 

 Fig. 7. — Natural size. 



Fig. 8. — Portion of a hydrocladium ; magnified. 

 Fig. 9.— Corbula. 



