606 COLLECTIONS FKOM THE WESTERN INDTA.N OCEAN. 



sible, readily torn. Colour pale brown ; general appearance that of 

 soft leather. Main skeleton composed of multispicular secondary 

 tracts of loosely aggregated spicules, 8- to 15-serial, placed parallel 

 to the surface at intervals of '2 to *3 millim., and of primary lines 

 represented by groups of 4 to 10 spicules crossing the intervals of 

 the secondaries, ladder-like, at intervals of about "3 millim., the 

 spicules composing these groups being so loosely associated as often 

 hardly to be in contact ; they turn to one side at the points at 

 which they come into contact with the secondaries, thus rounding 

 off the angles of the otherwise rectangular spaces of the meshwork. 

 Dermal skeleton formed by the outward projection of slender primary 

 tufts of spicules, 2 to 4 spicules broad. Sarcode pale brownish 

 yellow, subtransparent. Spicules smooth acerate, slightly curved, 

 tapering to sharp points from 2 or 3 diameters from ends ; size '18 

 by -007 millim. 



Hob. Seychelle Islands, 2 fms. ; Marie Louise Island, Amirante 

 group, 16-17 fms. ; bottom coral. 



This species, by its polys picular fibre and compact structure, differs 

 from most species of Reniera. Indeed the former character would 

 appear to ally it to Schmidtia ; but it is remarkable that, probably 

 in connexion with the thinness of the wall and consequent need of 

 resistance to lateral pressure, it is the secondary, and not tho primary, 

 fibres which are the stoutest ; possibly it is to the exigencies entailed 

 by the peculiar external form that the whole of the internal pecu- 

 liarities are due. The largest of the specimens, which are somewhat 

 fragmentary, measures 30 millim. high by 18 millim. in extreme 

 breadth. 



25. Reniera cribriformis. (Plate LIII. fig. G ; Plate LI V. fig. o.) 



Some fragments in spirit of a hollow cushion-shaped sponge seem 

 worthy of a description, as it has characters by which it may be 

 recognized. The wall is *5 to 3 millim. thick, compact, folded back 

 at the margin so as to enclose a space below the surface. Surface 

 very even and glabrous, perforated at intervals of 1-5 millim. by 

 circular vents, *5 to 2-5 millim. in diameter. Consistence elastic, 

 rather firm ; colour pale dull brown. Primary fibres of main skele- 

 ton about *18 millim. apart, vertical to surface, spicules 2-3-serial; 

 secondary fibre represented by separate spicides, traversing at various 

 angles the spaces between the primaries. Dermal skeleton a close 

 meshwork of irregularly disposed single spicules, not united to form 

 fibres. Sarcode transparent, almost colourless. Spicule smooth, sub- 

 cylindrical acerate, very slightly curved, tapering from near centre 

 to points of various degrees of bluntness ; size -2 by *007 millim. 



Hob. Seychelle Islands, 12 fms. ; bottom coral. 



This species seems to approach R. testud lixivia, Lamarck (see 

 Australian lleport), in the tendency of its spicules to assume the 

 cylindrical form. 



Carter's " Reniera, dark brown " from the Gulf of Manaar (Ann. 

 & Mag. N. H. 1880, vi. p. 48), differs decidedly from this in its 



