THE SPONGES OF THE WEST-CENTRAL PACIFIC 111 



Text Figure No. 70. Spicules 

 of Kallypilidion poseidon, X 

 781. A: Three of the oxeas. 

 B: Two spicules, perhaps juve- 

 nile, perhaps to be called raph- 

 ides. 



B 



The color in life was a vivid light blue, not at all greenish but rather 

 verging very slightly toward violet. The consistency was flexible, like that 

 of wet paper. 



The surface is mostly very smooth, but here and there a few small lumps 

 occur, about six or eight per specimen. The exterior of the bowl is covered 

 with compound pores, the skeletal pores being 400 /x to 500 \x in diameter and 

 the actual pores about 50 [x in diameter and separated from each other by only 

 very narrow strands. The exhalant apertures which cover the interior of 

 the bowl may be regarded as the oscules, although the upper opening of the 

 bowl might be so interpreted. These exhalant openings (apopores) are about 

 0.5 to 2 mm in diameter, and there is about one to each square mm. 



The ectosome consists of a tangental isodictyal reticulation, as charac- 

 teristic of the Adociidae, and the endosome is also strikingly isodictyal in 

 nature. 



The skeleton consists of spongin, which unites in reticulation the oxeas, 

 which latter are 2 \x by 64 fi to 3.5 /x by 77 /x in dimensions. A few much 

 smaller and thinner ones may be juvenile. In addition to the basal isodictyal 

 reticulation, there are present also tracts of fibers containing a moderate 

 amount of spongin. These tracts are 30 [x to 40 fx in diameter and consistently 

 about 200 /x apart. The rather rectangular meshes formed by these tracts of 

 fibers are visible to the naked eye when dried specimens of this species are 

 held to the light. 



The species name refers to the Greek deity Poseidon, called by the 

 Romans Neptune, who presumably reigned over the ocean. The suggestion 

 is here offered that such sponges as these might have been used by this sea 

 god as a head gear. 



GENUS ICHNODONAX, new 



This genus is here established in the family Adociidae, to have as geno- 

 type the species Ichnodonax kapne. It is characterized by a spiculation of 

 large oxeas, small strongyles, and palmate isochelas. It is placed in the family 

 Adociidae with some hesitation, because the dermis is not typical. Neverthe- 

 less there is enough of a dermal tangent reticulation that the family Desmaci- 

 donidae is contra-indicated. The nearest relative, however, may be the genus 



