168 
PACIFIC SCIENCE, Vol. XIX, April 1965 
Micros cleres. (i) Palmate isochelae, 8.0- 
1 4.5/a ( 12.25/a). 
(ii) Toxa of considerable range of size and 
shape, the smaller being tricurvate, the larger 
approaching raphides, very little flexed, and 
occasionally completely straight, rare; 33-137 /a 
(75/a). 
DISCUSSION: This species, both as described 
by Wilson (1925) and as represented in the 
Palau collection, is intermediate between Clath- 
ria Schmidt and Rhaphidophlus Ehlers in the 
features of the dermis. Levi (I960) redefined 
and maintained both genera, laying considera- 
ble stress on the tufted arrangement of the 
dermal spicules in Rhaphidophlus as opposed 
to the irregular, oblique to tangential arrange- 
ment in Clathria. The configuration of the der- 
mal spicules varies from place to place in Clath- 
ria fasciculata. Microciona eurypa has almost as 
well-developed a system of dermal brushes as 
has a typical Rhaphidophlus, and many other 
examples of this type of dermal specialization 
can be cited in Microciona in conjunction with 
the nonplumose skeleton which to a great de- 
gree characterizes the genus. It is difficult to 
differentiate clearly between Microciona and 
Clathria on the basis of the form of the skele- 
ton because of the existence of such intermedi- 
ate forms as Microciona prolifera; clearly, the 
dermal skeleton is too variable to be of sys- 
Fig. 22 a. Mycale lissochela n. sp. Left, Sta. 220A. 
USNM 23701; right, Sta. 220. Holotype. USNM 23702. 
tematic importance. For the latter reason Rha- 
phidophlus is not maintained as a genus dis- 
tinct from Clathria . The question of the pos- 
sible synonymy of Microciona and Clathria is 
not considered here since only detailed study 
of large collections and type material will suf- 
fice to resolve it. 
It appears from the material in this collec- 
tion that a firmer basis for the generic separa- 
tion of Rhaphidophlus would be to stress the 
great axial condensation with sharply demar- 
cated ectosomal and endosomal regions, rather 
than the notoriously variable dermal skeleton. 
DISTRIBUTION: Philippines (Wilson); Pa- 
lau Islands; Truk (de Laubenfels). 
FAMILY ophlitaspongiidae de Laubenfels 
genus Mycale Gray 
Mycale lissochela n. sp. 
Fig. 22 a, h 
OCCURRENCE: Sta. 220 (Holotype, USNM 
23702), 220A ( Paratype, USNM 23701). 
DESCRIPTION: Both specimens of this species 
are thickly encrusting, in one case over a hy- 
droid, in the other over a coral fragment. In 
specimen 220A the sponge contains many small 
zoanthids and around each of these the sponge 
dermis is raised in a membranous chimney. 
These do not appear to be the oscules, since 
groups of smaller openings lying flush with the 
sponge surface are common. 
DIMENSIONS (TABLES). 
COLOR: In alcohol, pinkish-gray (220 A) (Y- 
R 7/2) to (rY 8/4) pale creamy yellow (220). 
TEXTURE: Extremely soft and very slightly 
elastic. 
SURFACE: Smooth, and the dermis is variable 
in structure. In specimen 220A the fleshy tis- 
sues of the dermis are arranged so as to form 
a reticulate pattern; in the other specimen this 
pattern is only faintly discernible in isolated 
areas. For the most part the fleshy tissues are 
uniformly dispersed, and no pores or oscules 
are visible. 
SKELETON: Composed of thin curving 
sparsely branched tracts composed of subtylo- 
styles. Immediately below the surface the larger 
tracts break up into three or more divergent 
