SPON&IIDA. 445 



Torres Straits specimen. 



1. Slender acuate (slightly 



inflated basally) -25 to -31 by -0042 to -005 millim. 



2. Stout long acuate (very 



scarce) ' About -19 by -0095. 



3. Spined eohinating acu- 



ate -085 by -0044. 



4. Equiancborate -014 to -016 long. 



Hah. Prince of Wales Channel, Thursday Island, &o., Torres 

 Straits, 4-10 firns. ; bottom sand &c. ; common. 



From study of the present series of specimens, with the light 

 afforded by W. Marshall's important paper, " Untersuohungen iiber 

 Dysideiden und PhorioSpongien" (Zeitsch.wiss. Zool. xxxv. p. 122), 

 I am now convinced that Bowerbank was right in describing the 

 arenaceous material which is so plentifully present in this sponge 

 as the normal substratum of the skeleton-lines, and that it does not, 

 as I formerly considered (P.Z.S. 1881, p. 122), consist of the tubes 

 of an arenaceous Foraminifer. That' being so, the character assumes 

 a fresh importance when it is seen not to stand alone among the 

 Siliceous Sponges. Phoriospongia, Marshall {I. c), is described as 

 having a spiculation consisting of acerate and (or) spinulate and 

 bihamate spicules in combination with a large quantity of sand, the 

 latter, however, not aggregated into definite fibres. With regard to 

 Clathria tuberosa, though it diifers from other Glaihrice in this 

 remarkable point, its spiculation is distinctly that of the genus to 

 which I propose to refer it. 



76. Clathria coppingeri. 

 (Plate XL. figs. F, Y ; Plate XLII. figs, i, i'.) 



Erect, palmate, clathrous, growing in only one plane. A few 

 main branches are given off from the common base or rudimentary 

 stem, each dividing furcately once or twice at acute angles ; the 

 terminal branches are traceable to within about two thirds of the 

 distance from the base to the periphery of the sponge. All the 

 branches intimately united by a close reticulation, consisting of bars 

 of sponge-substance, suboblong in transverse section, the longest 

 diameter being the antero-posterior one, the anterior and posterior 

 surface of the bars either flat or coming to an angle in front or 

 behind or on both aspects ; the surface of the sponge thus presents 

 a series of subquadrangular, polygonal, or suboval cells, having 

 a maximum diameter of 3 to 10 millim.' Main branches suboblong 

 in transverse section, the antero-posterior diameter being longer 

 than the lateral one ; slightly marked by longitudinal furrows, the 

 anterior and posterior faces flat or angular ; the branches (espe- 

 cially the larger ones) project above the level of the intermediate 

 reticulation, owing to their superior antero-posterior thickness, which 

 attains a maximum of 20 millim., the lateral diameter a maximum 

 of 10 millim. Surface of intermediate reticulation, sides of main 



