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THE SPONGES OF THE WEST-CENTRAL PACIFIC 



from Ponape, at the time of collection, was brown. Inasmuch as it had 

 some other striking discrepancies, there is some doubt that it is the same 

 species or, if it is the same species, that it was in healthy condition at the time 

 of collection. It may have been pathological. The consistency was regularly 

 emphatically spongy. 



The surface, the pores, and the oscules are all impossible to describe in 

 view of the exceedingly peculiar architecture of this species and genus. 



The ectosome is as lacking as the pores and other surface structures. 

 The endosome (that is to say, the entire sponge) consists of a coarse reticu- 

 lation of fibers with the protoplasmic structures scarcely more than a film on 

 the surface of this reticulation. By squeezing this sponge, one could dislodge 

 the protoplasmic structures so that in a few minutes only a macerated skele- 

 ton remained. 



The skeleton of Kieplitela antrodes consists of fibers containing some 

 spongin and many spicules, often reaching a total diameter of 1 mm although 

 sometimes as small as 330 /a. The abnormal specimen, No. M. 444, had 

 small fibers only 130 jx in diameter. The spicules, which abundantly core 

 these fibers, are uniformly oxeas. These are about 3 /x by 90 p. in dimen- 

 sions in the type specimen and in the others from the Marshall Islands, 

 but from the more westerly islands — Ponape, the Palaus, and Guam — the 

 spicules are oxeas which commonly vary from about 6 ^ by 400 fi to 9 fi by 

 420 /a and even reach 7 p by 500 /a. In almost every specimen, a few much 

 thinner forms are present, but these may be juvenile. The fibers are echi- 



Text Figure No. 73. Spicules of Kieplitela antrodes, X 781. A and B: Oxeas. In each 

 case the entire spicule is shown, but in two parts. C: One of the echinating acanthostyles. 



