60 DESCEIPTIOX OF THE PLATES. 



contractile (?) bands are seen passing from the inner side of the hydrothecal valves to the body of 

 the hydranth. 

 Fig. 5. Portion of branch with front view of the hydrothecse ; magnified. 



Figs. 6, 7. Sertularella couica. 



Fig. 6. Natural size. 

 Fis. 7. Portion magnified. 



o o 



Fifs. 8-10. Sertularella amphorifera. 

 Fig. 8. Natural size. 



Fig. 9. Portion of a colony with gonangium ; magnified. 

 Fig. 10. Ilydrotheca stiU further enlarged. 



PLATE XVI. 



Figs. 1, 2. Sertularia marginata. 

 Fig. 1. Natural size. 

 Fig. 2. Distal end of colony, magnified. 



Figs. 3, 4. Sertularia tumida. 

 Fig. 3. Natural size. 

 Fig. 4. A portion, magnified. In one of the hydrotheca; the hydranth and two opercular bands are still 



visible. 



Figs. 5, 6. Sertularia tubitheca. 



Fig. 5. Entire colony, natural size. 

 Fig. 6. A portion, magnified. 



Figs. 7, 8. Sertularia ezigua. 



Fif. 7. Colony growing on a seaweed ; natural size. 

 Fig. 8. A portion, magnified. 



Figs. 9, 10. Sertularia distans. 

 Fig. 9. Natural size. 

 Fig. 10. A portion, magnified. 



Fics. 11, 12. Thuiaria sertularioides. 

 Fig. 1 1 . Natural size. 

 Fio-. 12. A portion, magnified. 



PLATE XVII. 



Fics. 1, 2. Thuiaria distans. 



Fio-. 1. Entire colony, natural size. 

 Fio-. 2. A portion, magnified. 



Figs. 3-6. Thuiaria plumulifera. 



Fig. 3. Entire colony, natural size. 



Fig. 4. Portion of a branch with pinnae, magnified. 



Fig. 5. Hydrotheca more enlarged, lateral view. 



Fig. 6. Same, front view. 



PLATE XVIII. 



Fig. 1. Natural size. 



Fio. 2. A portion with gonangia, magnified. 



Figs. 3, 4. Plumularia macrotheca. 



Fig. 3. Entire colony, natural size. 

 Fig. 4. A portion of a pinna, magnified. 



Figs. 5, 6. Plumularia attenuata. 

 Fig. 5. Natural size. 

 Fi". 6. Portion of stem with pinna, magnified. 



