332 A. E. Verrill— The Bermuda Islands; Coral Reefs. 
Most of the keratose sponges have been recorded in the memoirs 
of Prof. Hyatt. Those found on the reefs by my parties will be dis- 
cussed in the latter part of this chapter.* 
SILICIOUS SPONGES. 
The Bermuda silicious sponges are represented in our collections 
by about 38 species, but many of them have not yet been carefully 
studied and are not now enumerated. The reef species belong 
mostly to the Monaxonida, in which the skeletal spicules are 
unbranched ; but there are also several representatives of the 
Tetraxonida, in which part of the skeletal spicules have four 
branches, often in the form of anchors or grapples with three flukes 
and a long shank. Several species of this group, forming more or 
less spheroidal masses, with a radiate interior structure, belong to the 
Wesleyan University, and part in the U. 5S. Nat. Museum and Boston Soe. Nat. 
History, with Hyatt’s identifications, mostly made after his works were pub- 
lished. My own parties, 1898 and 1901, also made large collections. I have com- 
pared-most of our specimens of Keratosa with those labelled by Professor Hyatt. 
Many of the calcareous sponges (9 species, mostly dredged) were described by 
Poléjaeff in the Reports of the Voy. of the Challenger (vol. viii, part 24), but 
several others, found on the reefs, are in our collections. 
* The following are the principal ones hitherto recognized by me: 
Spongia lapidescens. Common: var. turrita Hyatt, very common: var. coni- 
fera Ver. (with finer texture and smaller and more regular cones). 
Spongia lignea, var. crassa Hyatt. 
Spongia anomala Hyatt. 
Spongia punctata, var. bermudensis Hyatt MSS. 
Spongia corlosia, var. elongata Hyatt. 
Spongia gossypina D, and M. (t. Hyatt). 
Spongia cerebriformis, var. obscura Hyatt. 
Hircina armata (D. & M., sens. ext.) Very common: var. fistularis V., var. 
nov., very common; it has hollow branches, with large terminal vents. 
Also varieties marginalis, cylindrica, columnaris, etc. 
Hircina acuta (D. & M.). 
Spongelia fragilis (Mont.)=Dysidea fragilis H. 
Dendrospongia crassa Hyatt. Common. 
Aplysina fistularis (Esper), Yellow tube-sponge. 
Aplysina hirsuta (Hyatt, as Verongia). 
Verongula pretexta (Hyatt, as Aplysina). This new generic name is proposed 
as a substitute for Aplysina Hyatt, for those species having regular, diver- 
gent, angular radial canals, with thin latticed walls, producing a honey- 
comb-like structure. It includes also: V., gigantea H.; V. rigida\D. & M.); 
V. cellulosa (H.); V. aurea (H.), ete. 
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