A. FE. Verrill—The Bermuda Islands; Coral Reefs. 339 
(c, ce’); the latter with the flukes minutely three-toothed. A few 
very long acute oxeotes, much larger than the other spicules (fig. 3, 
b, 6), were scattered through the sponge; perhaps they were extra- 
neous. Numerous minute circular disks (fig. 2, 2) were present, but 
disappeared when treated with acids; they are probably symbiotic 
alge. 
Family, Zedanidw. (P. 333.) 
Sub-family, Tedanine Ridley and Dendy ; Topsent, etc. 
Tedania ignis (D. and M.) Scarlet Sponge. Fig. 180. Plate xxxvo, fig. 4, 
spicules. 
Thalisias ignis Duch. and Mich., op. cit., p. 83, pl. xviii, fig. 1, 1865.* 
? Arcesias hostilis D. and M., op. cit., p. 97 (encrusting form). 
? Tedania digitata, var. bermudensis Ridley and Dendy, Voy. Chall., xx, p. 51. 
Amphimidon variabilis Maynard, Sponges, p. 31, fig. 19, pl. iv (colored), non 
Duch. and Mich. 
This is one of the most abundant Bermuda sponges and is very 
conspicuous in shallow water on account of its brilliant colors, 
which vary from bright scarlet to blood-red. In life it is very soft 
and brittle. When young it forms broad thin incrustations on rocks, 
dead corals, shells, and other sponges. Later it grows up into large 
irregular lobulate or convex massive forms, often with large conical 
or fistular elevations, each bearing a large terminal osculum. Some- 
times it is branched, or encrusts the branches of dead gorgonians, 
etc. It often penetrates into the cavities of dead corals and forms 
a red film over the surface, but there is no proof that it forms exca- 
vations for itself. When dry the surface is usually covered with 
rather deep, irregular, angular pits or areolations, 2-3™™" in diameter, 
with a small central pore, the ridges between being thin and sharp ; 
in some cases a thin dermal film remains over the areole. The 
interior is made up of small irregular angular and rounded reticula- 
tions of slender spiculose fibers, with irregular channels and lacune, 
some often of large size. The spicules are of several forms: 1. the 
spicules in the fibers are mostly long, slender styles and subtylostyles; 
2. oxeotes, acute at both ends; 3. smaller, slender, often bent, tylote 
spicules, with both ends slightly enlarged, which are abundant in the 
external layer, mixed with oxeotes; 4. very slender, long, acute, 
capillary forms (rhaphides) abundant, both singly and in fascicles. 
The larger spicules are .23 to .30™™ long. 
* This sponge has the several forms of spicules characteristic of Tedania 
(1867). But though Thalisias D. and M. antedated the latter, it was a heteroge- 
nous group, not intelligibly defined, and if adopted at all sogne other species may 
be taken as its type. 
