THE SPONGES OF THE WEST-CENTRAL PACIFIC 



169 



Text Figure No. 110. Spicules of Biemna mnioeis, X 782. A: Style; the entire spicule 

 is shown, but in two parts. B: Peculiar large sigmoid spicule. C : Commonplace sigmas. 



D: Raphides. 



The exterior color in life was a dark dull green. This did not stop 

 sharply but penetrated to a depth of 3 or 4 mm, gradually shading or blend- 

 ing into the yellow endosome. The consistency was slimy, somewhat like 

 wet bread, and it was very easily torn. 



The surface is exceedingly irregular and rugged. There are primary 

 rugosities about 2 or 3 mm in diameter and 2 or 3 mm high, so crowded that 

 the spaces between them are only 1 to 2 mm wide. Yet these protrusions are 

 in turn lumpy, with tubercles nearly 1 mm high and nearly 1 mm in diameter 

 all over the surface. The pores and oscules cannot be located in this con- 

 fused situation. 



The ectosome is characterized principally by the color and does not 

 differ sharply from the endosome, but there are more dense protoplasmic 

 structures right at the surface. The endosome is micro-cavernous. 



The skeleton consists chiefly of spicules in confusion. There are mega- 

 scleres which are smooth styles, 7 p. by 240 /x in dimensions, and there are 

 sigmas of two sizes and types. The larger ones are 1 /x to 2 ll in diameter 

 and 80 fi in chord length. There is a single semicircular curve, and at each 

 end of it a small recurved portion, so that the whole resembles the removable 

 handle of a bucket. Perhaps these should be regarded as toxas, rather than 

 as sigmas. The smaller sigmas are 28 ll in chord length and are rather typical 

 in shape. Raphides, about 28 /x long, sometimes aggregated into bundles, 

 also are present and therefore they might be called trichodragmas. 



Apparently there are two species of the genus Biemna in Ponape, but this 

 is subject to question, because it here is suggested that the species mnioeis 



