THE SPONGES OF THE WEST-CENTRAL PACIFIC 19 



The surface is conulose with conules 0.5 mm high and 1.5 mm apart. 

 The pores are microscopic and usually closed. The oscules are 1 to 2 mm 

 in diameter, round, and on the upper edge of the sheet. They most frequently 

 occur at the places where the sheets come together : at the corners of rooms, 

 so to speak. 



The ectosome is a debris-filled dermis about 200 /x thick and very simi- 

 lar on both sides of the sheet. The endosome is densely filled by a fine-mesh 

 f ibro-reticulation with small, round, flagellate chambers. 



The skeleton consists of primary fibers about 75 /a to 150 /a in diameter, 

 containing some foreign material, and also of abundant secondary fibers 

 about 25 it in diameter, devoid of debris. These make a close-meshed reticu- 

 lation with round openings only about 100 ti to 200 ^ in diameter. 



Within the genus Phyllospongia, the species complex is unique for its 

 shape, although the subspecies polyphylla of the species papyracea forms a 

 lettucelike mass of leaves. These do not form rooms in polyphylla, and the 

 oscules are on the surfaces rather than on the edges or rims. Yet, there is a 

 precedent for the shape of the species complex. In 1885, page 301, Lenden- 

 feld described Halme simplex from Australian waters and figured exactly 

 such an architecture (Monograph of Australian sponges, plates 26 and 27, 

 also see de Laubenfels, 1948, page 41), but on a finer scale and with walls 

 only about 1 cm high. Lendenfeld reports fibers scarcely cored with foreign 

 material and does not describe a debris-filled dermis. Therefore, de Lauben- 

 fels, 1948, page 40, placed this in the genus Hyattella. As E. F. Hallmann 

 has made very clear, Lendenf eld's descriptions are not merely verbose and 

 obscure but definitely unreliable, being replete with purely imaginary details. 

 Were specimens of his simplex available, it is conceivable that they might 

 prove to be congeneric, or even conspecific with complex. On the other hand, 

 they might prove to be even farther removed than seems to be the case. 



The species name refers to the complex shape of this species. 



GENUS POLYFIBROSPONGIA Bowerbank 

 Polyfibrospongia dysodes new 



Text Figure No. 9 



This species is here represented by the following : 

 U.S.N.M. No. 23136, My No. M. 519, here designated as type, collected on 

 September 8, 1949, by hand while wading in a bay on the west coast of 

 Babeldaub Island of the Palaus, 5 kilometers north of Ngeremetengel 

 Bay. The depth was less than 1 meter, and the substrate was mixed 

 coral debris and mud. 



The abundance of this species is not easily gauged, because of its super- 

 ficial resemblance to Spongia zimocca. The two, conjointly, were abundant 



