174 TIREE CRUISES OF THE “BLAKE.” 
was the first to show that the sponge and siliceous cable were 
one organism, and the polyps mere parasites attached to it above 
the mud and below the sponge (Fig. 528), a view which has 
been fully confirmed. Asconema setubalense, a magnificent sili- 
ceous sponge, first dredged by Kent off the coast of Portugal, 
has a wide geographical distribution. Very fine specimens were 
collected by the “Talisman,” and one of the adjoining figures 
Fig. 531. — Holtenia Pourtalesii. 2, 
(Fig. 529) is taken from one of the best preserved specimens 
of the French expedition. It is a common species in the West 
Indies, in from 300 to 600 fathoms. Pheronema Anna (Fig. 
530), first described by Leidy, is represented by some most 
