PLATE CXXI. 
PAGE 
Pigs. 1-9. Htdractinia multispinosa n. sp 433 
1. The type specimen, growing, as usual, upon the shell of Poly- 
nices sp. and showing the average external appearance. U. S. 
National Museum. 
2, 3. Two specimens showing extremes observed in number and size 
of surface spines. The latter possibly represent a distinct 
species or variety, approaching the European H. circum- 
vesticus (Wood). 
4-7. Surface of four specimens showing slight variations partly due 
to preservation. x 8 
8, 9. Edge views of four pieces of two specimens showing interla-- 
minar spaces and other characters very well. The solid lower 
portions of the two upper pieces represent the space of the 
absorbed shell replaced by nearly solid coral tissue. U. S. 
National Museum. Plum Point. X 8 
Fig. 10. MiLLEASTER iNCBUSTANS n. gen. et. sp 436 
10. Surface of a specimen. U. S. National Museum. Plum Point. 
Figs. 11a, lib. MiLLEASTER (?) SUBRAMOSUS n. sp 437 
11a. The type specimen. Cove Point. 
lib. Another view of the same. The large openings are of small 
barnacles partly covered by the hydrozoan. x 4 
