Sponges of Palau, I — BERGQUIST 
169 
FIG. 22 b. Mycale lissochela n. sp. Spicules: 1, Sub- 
tylostyles. 2, Sigmas. 3, Palmate anisochelae. 
branches. Interstitial megascleres are abundant 
throughout the sponge and occur tangentially 
disposed in the dermal membrane. Microscleres, 
sigmas, and isochelae, occur throughout the 
sponge; sigmas are particularly abundant in the 
dermis. 
Fibres range from 10-75/x in diameter. 
The construction of the sponge is relatively 
compact; there is no development of huge sub- 
dermal or interfibrillar spaces as in many 
myealids. 
spicules: Megascleres. Subtylostyles, straight 
or very slightly curved with elongate oval heads; 
212-275 (252) X 3. 0-4.5 /x (3.6/x). 
Microscleres. (i) Sigmas, C-shaped with 
sharply reflexed tips, which are frequently in 
different planes; occasional S-forms occur. These 
spicules are abundant throughout the flesh and 
in the dermal membrane; 19-40/x (33.9/x). (ii) 
Palmate anisochelae, small spicules with thin 
alae; 3.0-3. 5g wide, 13-20 /x (16.2/x) long. 
DISCUSSION: Burton (1956) has drawn at- 
tention to a group of species within Mycale 
which have in common (a) small narrow 
anisochelae 9 of one size group only, (b) a 
single category of sigmas which are approxi- 
mately twice the size of the chelae, (c) tylo- 
styles or subtylostyles between 200-300^. To 
this list of characters Burton adds a fourth, "the 
spiculation of Topsent’s subgenus Carmia'.' This 
statement is quite misleading, as none of the 
species Burton then proceeds to list has the 
spiculation of Carmia. 
Mycale lissochela is extremely close in spicu- 
lation and structure to Mycale cecilia de Lau- 
benfels, M. micro si gmatosa Arndt, Mycale sene - 
galense Levi, and M. phyllophila Hentschel, 
and is comparable to M. angulosa (D. and M.),, 
M. fistulata Hentschel, M. serpens (Lenden- 
f eld ) , and M. tenuispiculata ( Bendy ) . The last 
four species, however, are massive rather than 
encrusting. 
Mycale angulosa is comparatively well known; 
it has a distinctive habit, cavernous architec- 
ture, and rare microscleres. Thus, despite close 
similarity in spiculation to the other species 
mentioned it can certainly be maintained as a 
separate species. Mycale cecilia cannot be dis- 
tinguished from M. microsigmatosa and the lat- 
ter can only be considered distinct from AL 
phyllophila Hentschel on the grounds of distri- 
bution. Levi (1959) has already indicated that 
his M. senegalense is probably synonymous with 
M. microsigmatosa Arndt. M. maunakea de 
9 Burton’s text reads ''isochelae, ” which I have inter- 
preted as a misstatement; it is confusing, however, as 
some species of Mycale are reported to have isochelae. 
TABLE 8 
THICKNESS 
LENGTH 
WIDTH 
OSCULES 
SPECIMEN 
(cm) 
(cm) 
(cm) 
(mm) 
Sta. 220 
0.2-0.35 
broken 
— 
not apparent 
Sta. 220A 
0.3-1. 1 
7.5 
1.5-3. 5 
0.4-0.6 
