160 THE SPONGES OF THE WEST-CENTRAL PACIFIC 



The color in life was vivid red, a tint often called carmine. The interior 

 was darker than the exterior in the thicker specimens. The consistency 

 was soft and could be compared to wet paper. 



The surface is fundamentally smooth but is microscopically velvet-like or 

 hispid. It is lipostomous, but the occurrence in places of obvious subdermal 

 spaces making patterns somewhat like miniature river systems indicates the 

 probable existence of oscules at the terminations of these rivers. These os- 

 cules were already closed upon collection. 



The ectosome consists of a very definite dermis, rather easily detached 

 from the underlying tissue. The thickness of its flesh is only about 10 /x or 

 20 ix. In this ectosome, many of the spicules are erect with points out; 

 others are in confusion. The spicules in the endosome are also chiefly in 

 confusion, but it is probable that the faint pattern which occurs appropriately 

 may be described as slightly plumose. 



The skeleton consists of megascleres and microscleres. The former are 

 smooth straight tylostyles with such blunt points that all of them approach, 

 and some of them actually reach, the shape which may be termed tylo- 

 strongyle. The dimensions range from 3 /x by 233 fx to 5 [x by 310 /x. The 

 microscleres are strongly curved anchorate isochelas of two size ranges. 

 The largest size is about 30 /x in chord length and is very thick, up to at 

 least 5 [x. The isochelas in the smaller size range are about 15 ju in chord 

 length and are exceedingly thin, in many cases less than 1 \x thick. 



The only other species hitherto described in the genus Folitispa is that 

 which was first described as Hymedesmia laevissima by Dendy, 1921, page 

 81, from the Indian Ocean region. It had spicules far larger than those of 

 pingens. They were up to 20 [x by 660 jx in dimensions. 



O 



O 



f\ 



_ r 



B ^ 



D 



Text Figure No. 104. Spicules of Folitispa pingens, X 782. A : Tylostrongyle. B : Tylo- 

 style. C: Arcuate isochelas of larger size. D: Smaller isochelas. 



