182 
PACIFIC SCIENCE, Voi XIX, April 1965 
synonymy of Acanthoxifer and Myrmekioderma 
and removed the Heteroxyinae to the Desma- 
cidonidae (Subfamily Axinellinae, section Het- 
eroxyeae). Topsent (1928) elevated the Het- 
eroxyinae to family rank, added Anacanthaea 
Row, and endorsed the relationship of the 
group to the Axinellidae. Burton ( 1937 ) placed 
Myrmekioderma in his section Raspelieae, 
which includes all axinellid families. 
Wilson (1925) was unaware of the synon- 
ymy of Acanthoxifer with Myrmekioderma and 
referred Acanthoxifer and Anacanthaea to 
Spongosorites Topsent on the basis of Dendy’s 
(1905) redefinition of this genus and informa- 
tion derived from stiidy of a new sponge, 
Spongosorites suluensis Wilson. Wilson urged 
the relationship of the above sponges to the 
Epipolasida, as Jaspidae without microscleres. 
De Laubenfels (1936) has in part sustained 
this view in making S . suluensis Wilson the 
type of Epipolasis, which is placed in the Solla- 
sellidae. This cannot, however, apply to Acan- 
thoxifer and Anacanthaea; these sponges have 
their closest relatives in the genus Higginsia, 
to which they are closely allied in Dendy’s 
1922 classification. Wilson’s reason for uniting 
the genera is that S. suluensis has tangential 
dermal oxeas on the oscular face ( see Spongoso- 
rites sensu Dendy) and oxeas in radial brushes 
on its pore face; these characters are compared 
to Acanthoxifer and Anacanthaea. This is a 
simplification which entirely overlooks previous 
synonymy and certain structural features, such 
as the presence of a vague fibrous structure in 
the choanosome of Acanthoxifer ( Myrmekio- 
derma ) accompanied by traces of spongin, and 
the variable disposition of the dermal oxeas in 
this genus. Anacanthaea does not possess a 
separate category of dermal oxeas. Further- 
more, both genera share the distinctive surface 
pattern of polygonal tubercles delimited by 
pore grooves (Fig. 21a, b) . None of these fea- 
tures has been recorded for Spongosorites. 
Wilson was correct in his assessment of the 
systematic position of S. suluensis ; 12 he was in 
error in assuming Spongosorites to be a homo- 
geneous genus. A proper evaluation of the re- 
12 The type specimen of this sponge, USNM 21297, 
has been re-examined. 
lationships of Spongosorites Topsent and Epi- 
polasis de Laubenfels is urgently required but 
must await the restudy of type material. 
De Laubenfels (1936) placed Acanthoxifer 
in the Epipolasida (Rhaphidistinae) , Heteroxya 
in the Coelosphaeridae, Anacanthaea in the Ax- 
inellidae, and Myrmekioderma in the Phorbasi- 
dae, thereby rejecting the opinions of all pre- 
vious authors. In the case of Heteroxya and 
Myrmekioderma he expressed doubts as to their 
correct placing; in the case of Acanthoxifer he 
misread the type description; Anacanthaea was 
placed with the axinellids on. the tenuous 
ground that the spiculse are stairstepped and 
mucronate. 
It is not at all clear that Heteroxya Topsent 
is as close to Myrmekioderma and Anacanthaea 
as Dendy considered. Heteroxya has in com- 
mon with the other two genera a densely spic- 
uliferous cortex composed of radially disposed 
acanthoxeas, a hispid surface, and the large, 
smooth oxeas. It differs in morphology of the 
surface, in the scarcity of endosomal mega- 
scleres, lack of raphides, and in spicule size 
and shape. There is no mention of variability in 
spicule terminations in Heteroxya as reported 
for Myrmekioderma. The endosomal mega- 
scleres in Heteroxya are extremely large (2000 
X 35g) and project beyond the surface; the 
acanthoxeas are 235 X 12-23/*, much stouter 
than in Myrmekioderma. None of the above 
features, however, supports a coelosphaerid af- 
finity for Heteroxya as de Laubenfels suggested. 
At present the morphological evidence sup- 
ports Dendy’s decision that Myrmekioderma 
and Anacanthaea, with the possible addition of 
Heteroxya, should be placed near Higginsia, in 
a family close to the Axinellidae. 
DISTRIBUTION: East Indies (Esper); Gulf of 
Manaar (Dendy 1905, Burton 1937); Coetivy 
(Dendy 1922); Truk, Ponape, Ebon (de Lau- 
benfels ) ; Madagascar, Aldabra ( Levi ) . 
ORDER HADROMERIDA Topsent 
FAMILY SPIRASTRELLIDAE Hentschel 
genus Spirastrella Schmidt 
Spirastrella aurivilli Lindgren 
Fig. 28 a, b 
