32 
PACIFIC SCIENCE, Vol. IV, January, 1950 
is much like diploderma but less elaborate 
as to dermis, and its micrasters each have a 
centrum. It is a western Pacific species, from 
Japan through the East Indies to New Zea- 
land. The species diploderma is circum- 
equatorial. If the two should be determined 
to be conspecific, as is possible, the name 
diploderma has a 28-year priority. 
Zapletfiea new genus 
This genus is erected with the following 
species, Zaplethea digonoxea, as genotype. It 
is placed provisionally in the family Haii- 
nidae, subfamily Corticiinae. It should be 
emphasized that this is a genus of sponges 
with extremely abundant microscleres, but 
very few megascleres, those that are present 
being oxeas. The microscleres are of two 
sorts, euasters and twice-bent microxeas. 
Twice-bent spicules are exceedingly rare 
in the phylum Porifera. There is at least one 
other case, however. This is the record by 
de Laubenfels (1930: 26; or better, 1932: 
35) of Penares cortius, a sponge with two 
kinds of microscleres: euasters and twice-bent 
microstrongyles. It had a few oxeate mega- 
scleres, so that if the twice-bent spicules were 
oxeate, there would be agreement to this ex- 
tent. However Penares has a principal spic- 
ulation of large tetraxons; thus it goes in the 
order Choristida. Penares cortius, from Cali- 
fornia, was a large sponge with a conspic- 
uous leathery dermis, very different in appear- 
ance from Zaplethea digonoxea. 
In the order Choristida there is a family 
Jaspidae. Its type genus, J as pis, has a spic- 
ulation of oxeas and euasters, but no twice- 
bent microscleres; the oxeas are the princi- 
pal spicules, and are radiately arranged. 
These are large, significant differences from 
Zaplethea. 
The order Carnosa is established especially 
to receive sponges that have few or no meg- 
ascleres, and has even been called "Micro- 
sclerophora.” Thus it seems clearly to be the 
best order to receive the genus Zaplethea 
Yet the family situation in this order is still 
perplexing; there are now four families in 
the Carnosa, and none quite fits Zaplethea. 
The Chondrosiidae have no spicules at all. 
The Chondrillidae have only euasters. 
The Plakinastrellidae have a few mega- 
scleres, as no others in the order do, and thus 
are intermediate. But the megascleres that 
are present are tetraxons, so that the inter- 
mediate condition obtains as between the 
Carnosa and the Choristida. For lack of 
tetraxons, Zaplethea seems utterly out of 
place in the Plakinastrellidae. 
The fourth family is the Halinidae, here 
selected by elimination. Yet all the genera 
of this family ( there are about a dozen ) have 
a peculiar microsclere known as calthrops. 
Other than this, these genera are divided into 
two subfamilies; the Halininae have asters 
that are streptasters, while the Corticiinae 
have asters that are euasters. 
If we focus attention on the above- 
mentioned fact that every other genus in this 
family has calthrops, and regard this as a 
reason for excluding Zaplethea, we are 
thrown into the embarrassing situation of 
needing a new family to receive this genus. 
I do not want to erect any more families in 
the Porifera, because I believe there is a large 
enough number already. 
The genus name is derived from the Greek 
"zaplethes,” meaning very full, because the 
sponge is so packed with spicules. The exact 
Greek is not available, having been used in 
1868 in Hymenoptera, also in 1920 in Pisces. 
Zaplethea digonoxea new species 
Fig. 21 
The holotype of this species is designated 
as spirit-preserved specimen, U. S. National 
Museum, Register Number 22746. It was 
collected September 27, 1947, in Waialua 
Bay, at a depth of between 4 and 8 meters, 
growing on dead coral. A second specimen 
was collected in Kaneohe Bay on January 10, 
