New Sponges from the Yap Archipelago 
M. W. DE Laubenfels 1 
The Yap Archipelago is located east of the 
Philippines, in latitude 9° 35' N and longi- 
tude 138° 15' E. It is basically of rocky forma- 
tion with an extensive fringing reef of live 
coral, which encloses a lagoon-like harbor and 
tidal-flat region at each end of the small archi- 
pelago. 
In the summer of 1946 R. W. Hiatt of the 
University of Hawaii collected invertebrates, 
especially decapod crustaceans, in and about 
Yap. On two species of dromiid crabs he found 
interesting new species of sponges. He also 
collected a third species of sponge which is 
probably not a new species. 
Spongosorites porites, new species 
The holotype of this species is catalogue 
number 22732 of the United States National 
Museum. 
This was collected in July, 1946, by R. W. 
Hiatt, on a dromiid crab of the genus Crypto- 
dr omia, found in holes in dead coral on tidal 
flats in Tomil Harbor, on the island of Yap. 
Shape: A smoothly rounded mass. 
Size: Approximately 10 mm. thick, 15 mm. 
in diameter. 
Color: Black. In many sponge species there 
are many cells with darkly pigmented granules 
located within 1 mm. or less of the surface of 
the mass or right at it. In Spongosorites porites 
such cells are rather uniformly distributed 
throughout the sponge although they are some- 
what more densely grouped near the surface. 
Consistency: Weakly spongy. 
1 Department of Zoology and Entomology, Univer- 
sity of Hawaii. Manuscript received July 3, 1948. 
Surface: Smooth to the naked eye, micro- 
scopically felted. 
Oscules: Barely visible to the naked eye, 
probably close to 300 microns in diameter when 
fully opened, in life. About a dozen on the 
specimen. 
Pores: Microscopic, contractile, chiefly closed 
in the specimen. 
Ectosome anatomy: As in the Haliclonidae, 
and to a lesser extent in some Axinellidae, there 
is practically no dermal specialization. The 
rather dense endosome extends to and forms 
the surface. In many places there is a region 
about 100 microns thick, right at the surface, 
where there is a confusion of many spicules 
but no flesh. This may be an accidental condi- 
tion. No subdermal space could be found. 
Endosome anatomy: The flesh is dense, with 
a preponderance of heavily pigmented granules. 
The spicules are also densely crowded, so that 
very little cavity of any sort remains. 
Skeleton: The abundant spicules are prac- 
tically all oxeas. An occasional rounded end is 
almost certainly accidental. The megascleres 
are all close to 6 by 300 g. The microscleres 
range from 2 by 50 to 3 by 75 g, and often have 
a single bend in the middle, so that they vaguely 
resemble toxas. 
Discussion: Topsent (1896: 117) established 
the genus Spongosorites for the one species 
placenta. This came from a depth of 550 meters 
in the Atlantic Ocean near the Azores. As com- 
pared to porites, it is paler, harder, and the 
smaller category of spicules has a size range 
about 5 by 70 g. Topsent also describes the 
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