Sponges of Kaneohe Bay — DE LAUBENFELS 
33 
1948, at a depth of 2 meters, also on dead 
coral. 
This species is encrusting, about 3 to 5 mm. 
thick. The color is pale, dull, and may be 
termed drab, or yellowish-gray. The consis- 
tency is firm, somewhat like cartilage. The 
surface is smooth and lipostomous. There is 
no sharply defined cortical region. The «.n- 
terior is exceedingly dense, with few cavities 
larger than 40 g in diameter. The flagellate 
chambers are about 25 g in diameter. 
ft B 
Fig. 21. Zaplethea digonoxea, spicules, from a 
camera lucida drawing, X 444. A, microxeas. 
B, euasters. The larger oxeas are not shown. 
There are a few scattered oxeas, 7 by 400 
to 12 by 520 g in size. They are so rare 
that while I had only the one specimen I 
considered them accidental, foreign inclu- 
sions. But they were not only present in the 
second specimen, they were a little more 
nearly common in it. The whole sponge is 
densely packed with millions of microscleres. 
They are of two sorts, about equally abun- 
dant. One kind is an oxyeuaster, usually 
10 g, but ranging on up to 20 g, in diameter. 
The other very distinctive kind is a twice-bent 
microxea. The three straight regions make 
obtuse angles and are not quite equal in 
length; instead the middle piece is a little 
longer than the others. The over-all length 
is about 105 g and the thickness 3 g or less. 
The species name stresses the twice-bent 
microxea; in fact, this novel sort of spicule 
itself may suitably be named digonoxea. 
Plakortis simplex Schulze 
Fig. 22 
This species was found in Hawaii on Janu- 
ary 10, 1948, in Kaneohe Bay, at a depth of 
about 2 meters, growing on dead coral. An- 
other specimen was found on May 15, 1948, 
at Keaukaha near Hilo on the island of 
Hawaii, just below low tide mark. 
This is a thin, encrusting sponge, seldom 
much more than 2 mm. thick. The two 
specimens covered about 10 square cm. each. 
The first was dull olive-brown, the second 
dull gray — this species is usually brown, but 
dull or drab. The consistency is rather like 
that of cheese. 
The surface is smooth but not level, being 
often elevated into low tubercles. As usual 
in such thin sponges, -it is lipostomous. There 
is a paper-thin fleshy dermis; the rest of the 
sponge is also very dense. It is astonishingly 
full of flagellate chambers which are round 
and are 30 to 40 g in diameter. The spicules 
are crowded throughout the flesh in confu- 
sion. Much of the skeleton is merely the 
usual interstitial jelly. 
Fig. 22. Plakortis simplex , spicules, from a 
camera lucida drawing, X 380. A, oxeas (?). 
B, triaxons. 
The spicules of Plakortis are chiefly to be 
regarded as triacts, and about one in twenty 
is indeed a neat, symmetrical triact as in cal- 
careous sponges. The rays are often about 
5 to 7 by 100 g. More common are spicules 
that show signs of being a triact with one 
ray missing, so that the result is V-shaped. 
Very much the commonest of all are spicules 
that seem at a casual glance to be oxeas, but 
which have a central swelling or series of 
