Sponges' of Palau, I — BERGQUIST 
181 
spherical flagellate chambers, 2.3-30/x in di- 
ameter. 
DISCUSSION: Bendy (1922) suggested the 
possible synonymy of his genus Acanthoxifer 
with Myrmekioderma Ehlers, the only differ- 
ence between the two being the presence of 
trichodragmata in Acanthoxifer . Burton (1937) 
and Levi (1961) have adopted this synonymy. 
Be Laubenfels (1936), however, retained 
Acanthoxifer as a genus of the Rhaphidistinae 
but based his decision on a misinterpretation, 
having regarded the acanthose megascleres as 
a second category of microscleres which he 
termed "spiny microhabds.” Be Laubenfels 
(1954) recorded Myrmekioderma granulata 
(Esper) from Truk and described a new spe- 
cies, Myrmekioderma tylota, from Ponape, the 
latter differing from M. granulata in having 
small "tylotes” as microscleres instead of tricho- 
dragmata. In the same work a new genus of 
Hymeniacidonidae, Neoprosypa, was erected 
for the single species, Neoprosypa atina. 
Comparison of the type specimens of Myr- 
mekioderma tylota and Neoprosypa atina with 
de Laubenfels’ specimens of Myrmekioderma 
granulata (see table) reveals that all these 
sponges are identical. The "small tylotes” of 
M. tylota are diatoms; further, trichodragmata 
do occur in this species. 
A spicule preparation of the holotype of 
Acanthoxifer ceylonensis Bendy shows a very 
similar range in variation of spicule size and 
shape to that found in de Laubenfels’ and in 
my Pacific specimens. Further, the surface fea- 
tures and skeletal arrangement correspond in 
detail. 
Levi (1956) described Acanthoxifer four- 
manoiri from Madagascar and considered this 
distinct from Acanthoxifer ceylonensis Bendy 
in having longer raphides making up the tricho- 
dragmata and a tangential or oblique arrange- 
ment of dermal acanthoxeas. Bendy mentioned 
that many of the dermal spicules were obliquely 
disposed in A. ceylonensis. This disposition is 
characteristic of the sides of the surface tuber- 
cles in all of de Laubenfels’ specimens and 
those from Ifaluk and the Palaus. With the 
description of a specimen of Myrmekioderma 
granulata from Alda bra, Levi ( 1961 ) provided 
data which reduced the gap between the raphide 
dimensions of A. fourmanoiri and other speci- 
mens of M. granulata from Ceylon and the 
central Pacific. The Palau specimens possess 
long raphides, as do de Laubenfels’ specimens. 
The differences are not what they appear to be 
from the literature and do not justify the divi- 
sion of this genus into separate species. 
In the generic diagnosis of Neoprosypa de 
Laubenfels states that "all or nearly all of the 
megascleres are completely acanthose.” This is 
an error; the type specimen of N. atina has the 
minutely acanthose megascleres and also the 
smooth endosomal megascleres characteristic of 
M. granulata. The ectosomal megascleres are 
clearly set off from the endosome in Neopro- 
sypa atina, but they tend to be oblique over 
large areas due to the extremely irregular habit 
of the sponge. In this respect N. atina ap- 
proaches A . fourmanoiri Levi, Ehlers’ (1870) 
redescription of Alcyonium granulatum Esper 
makes no mention of trichodragmata; these, 
however, are rare and inconspicuous in every 
Pacific specimen examined and, as de Lauben- 
fels (1954) has pointed out, they could easily 
have been overlooked. 
The position of Myrmekioderma styx de Lau- 
benfels from the Gulf of Mexico is problematic. 
The holotype has been re-examined and few 
differences can be found to separate this spe- 
cies from the Indo-Pacific M. granulata. The 
surface is more coarsely and irregularly tuber- 
culate and the skeleton is a vague and irregu- 
lar endosomal reticulum of acanthoxeas broken 
by dense tracts of large oxeas and acanthoxeas, 
running vertically toward the ectosome. In the 
ectosome the acanthoxeas are either vertical in 
brushes, vertical but densely packed, or tan- 
gential to oblique. It is impossible to separate 
this specimen from others assigned to M. gran- 
ulata on the basis of spiculation, and skeletal 
and surface differences are not conclusive. In 
view of the geographic discontinuity between 
M. styx and other specimens assigned to M. 
granulata the two species are retained at present. 
The systematic position of Myrmekioderma 
Ehlers has been frequently debated. Bendy 
( 1905 ) created the subfamily Heteroxyinae 
within the Haploscleridae to receive Heteroxya 
Topsent and Acanthoxifer Bendy ( = Myr- 
mekioderma) . In 1922 Bendy suggested the 
