A. FE. Vervill—The Bermuda Islands; Coral Reefs. 333 
genus Sfelletta; some of them occur under large flat stones, others in 
sand. A large species, growing in hard, thick, lobate crusts on the 
reefs, is Geodia gibberosa ; its hard cortex is filled with spheroidal 
spicules (sterrasters), fig. 176. Also one of the fleshy sponges. 
Oligosilicina. FEleshy or cartilaginous sponges, without a skele- 
ton, but usually with abundant, minute, star-shaped flesh-spicules, 
with many rays (euasters). Family, Chondrillide. 
MONAXONIDA. 
Some of these are conspicuous on account of their large size or 
brilliant colors, like the very common scarlet sponge (Zedania); or 
have characteristic forms, like the tube-sponges (Spinosella), but 
many are inconspicuous and have irregular or incrusting forms. 
This order is represented here by several groups, mostly distin- 
guishable by their spicules : 
1. Chalinoidea, or Honorhaphida, in which the spicules are 
nearly all of one kind, usually fusiform, acute at both ends (oxeu), 
and enclosed in or held together by reticulated horny fibers ; no 
flesh-spicules (microscleres). Families, Chalinide and Renieride. 
2. Heterorhaphida, i which the skeletal spicules may be of two 
or more forms, usually oxeotes (oxea), combined with needle-shaped 
forms (styles), pin-shaped forms (tylostyles); with a head at both 
ends (tylotes); or with both ends blunt (strongyles). With these 
there are usually minute flesh-spicules, generally either C-shaped 
(sigmas or sigmata); bow shaped (toxa); or slender hair-like forms 
(rhaphides) ; but never anchor-like (chele). Families, Zedanide, 
Desmacellide, Gelliodide. 
3. Desmacidontoidea. In this family the skeletal spicules may be 
of various forms: styles, tylostyles, oxea, etc., but the flesh-spicules 
are minute anchor-like forms (chelz) with hooks or flukes at both 
ends; sometimes these are combined with sigmata, etc. The skeletal 
spicules are usually enclosed in horny fibers. Family, Zsperellidie. 
4, Kehinonemata. In.these, spicules project as special spines from 
the surfaces of the fibers: they are usually styles or tylostyles, often 
spinulated. Families, Agelaside (= Ectyonide), Clathriude. 
5, <leinelloidea, Usually branched sponges with distinct axial 
fibers, which are plumosely branched and filled with styles, stron - 
gyles, or oxea. Flesh-spicules seldom present, sometimes spirasters 
or asters; never chele. Family, Awinellide. 
6. Clavata or Suberitoidea. Massive, lobate, or boring sponges ; 
p) 
skeletal spicules mostly tylostyles or styles ; often no flesh-spicules ; 
Trans. Conn. Acap., Vou. XII. 22 May, 1907. 
