202 



THE SPONGES OF THE WEST-CENTRAL PACIFIC 



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Text Figure No. 136. Spicules of Anthosigmella vagabunda. A: Tylostrongyle, X 182. 



B: Head of common tylostyle, X 782. C: Spirasters with blunt spines, X 782; while not 



the commonest sort, they are distinctive. D: Tylostyle with swollen shaft, X 182. 



E: Commonplace spiraster, X 782. 



mens were found rising up as much as 25 cm. In such cases the diameter might 

 be as great as 15 cm. 



The exterior color in life varied from an ochraceous brown to walnut 

 brown ; the interior was always somewhat paler, and occasionally more yellow- 

 ish. The consistency was between spongy and fragile. 



The surface is smooth, undulatory, and micro-punctiform. The pores are 

 about 40 jx to 80 /x in diameter and often only 100 p apart. Occasionally, they 

 are 300 fi to 400 p apart. The oscules vary from 4 to (more commonly) 12 

 to 16 mm in diameter and are located conspicuously at the summits of the 

 digitate processes or subconical cylinders described above. Not only is the 

 location of itself conspicuous; but the lining of the cloaca of each oscule is 

 dark, and the exterior around the oscule is consistently a pale yellow color 

 for a distance of from 1 to 5 or 6 mm away from the rim. This brings the 

 oscule into extremely noticeable prominence. 



The ectosome is characterized by a dense spicular structure. Often the 

 spicules (megascleres) are somewhat smaller than those of the endosome, 

 and they usually have their points directed towards the surface. Thus, there 

 is a suggestion of resemblance to the genus Suberites. The endosome is char- 

 acterized by spicules which are almost always in complete confusion. 



The skeleton consists chiefly of tylostyles, which may be as large as 

 27 jx by 600 /a, although often they are only 8 p by 500 jx. It is noteworthy 

 that a few of them are styles, but these are then of the same size range as the 

 tylostyles. The microscleres are not numerous and are usually rather typical 

 spirasters. It is quite significant that a number of them are not typical 

 spirasters but instead are characterized by very blunt projections, rather to be 

 called tubercles than spines. Furthermore, many of these microscleres, instead 



