DICTYONINE HEXACTINELLID SPONGES 189 



In one of the two species described these meshes are somewhat 

 larger in vertical diameter and many retain a rectangular form, 

 but the branches freely inosculate and the quadrate form is not 

 long maintained. An examination of the accompanying figures 

 will show that these bodies present an aspect somewhat similar 

 to that of a D i c t y o n e m a, which is however purely simula- 

 tive. Found among dictyosponges, their skeleton is preserved in 

 like manner to those. 



Order HEXACTINELLIDA 



Suborder Dictyonina 



Family Nepheliospongidae, fam. nov. 



Vase-shaped sponges, moderately thick-walled as indicated by 

 the incurvature of the aperture. The tissue of inosculating spi- 

 cules divides the surface into small, irregular polygons. 



Genus nepheliospongia, gen. nov. 



With the characters above specified. Surface smooth, free of 

 ornamental protuberances or prostalia; in one species apparently 

 corrugated horizontally. Apertural edge rounded and broad. 



Type: Nepheliospongia typica, sp. nov. 



Nepheliospongia typica, sp. nov. 



Plate 10, fig. 1-3 



This species takes on the form of a rather small, obconic cup, 

 expanding with apparent regularity and evenly convex surface. 

 The meshes of the surface are not all so polygonal as represented 

 in the figure, but some show a more distinctly quadrate outline. 

 Though the cups of two specimens have been somewhat com- 

 pressed, one shows the aperture complete, and the fact that the 

 sponge wall appears to have possessed a somewhat greater thick- 

 ness than in the dictyosponges. The specimens of this species 

 found have the following dimensions. One has a length from 

 aperture to near the original base of 41 mm; its aperhiral width 

 is 34 mm. The other is about 2.^) mm long, having been broken 



