130 THE SPONGES. 



the former. The oxeas are chiefly confined to the spiculo-libre of the 

 interior, the strongyles to the surface layer. Ilahitat, Singapore. 



Under the head of Rhizoclialina singaporensis Carter var., Ridley (1884) 

 describes specimens " in which a large proportion of the (usually acerate) 

 spicules have both ends more or less rounded." "The largest adult spicules 

 have nearly the same size as the acerates o^ R. Jistulosa, viz., .3 x .0127 mm., 

 but they vary immensely in length." Habitat, Prince of Wales Channel, 

 West and Alert Islands, Torres Straits, 7 fathoms. 



Ridley and Dendy (1887, p. 34) record under Rhuochallna singaporensis 

 Carter a fistula taken by the "Challenger" (locality imcertain). I have 

 examined this specimen, and in my preparations the spicules were nearly 

 all strongyles. In the skeletal arrangement and color this specimen differs 



from 0. hacillifera. The sponge identified by Lindgren (1898, p. 297, 



Taf. 19, Fig. 11 a-b) as Rhizoclialina singaporensis Carter must, from the 

 present standpoint of classification, be placed in another genus, since it 

 has chelae. 



In the color and general appearance the fistulae, here described as 

 0. hacillifera, are very similar to fistulae taken off Bahia by the " Chal- 

 lenger," and referred, with a query, by Ridley and Dendy (1887, p. 34) 

 to Rhizochalina putridosa (? Lamarck), but in these specimens the spicules 

 are oxeas, and the reticulate character of the skeleton is strongly marked. 



Gellius Gray. 



1867. Gellius Gray, 1867, p. 538. 



1887. Gellius Gr&j pars, Vosmaer, 1887, p. 349. 



1887. Gellius Gray, Ridley & Deudy, 1887, p. 37. 



1894. " " Topseut, 1894 a, p. 8. 



1894. " " Dendy, p. 247. 



1902. " " Luudbeck, p. 62. 



Gellius perforatus, sp. nov. 



Plate 17, Fig. 11; Plate 18, Fig. 1; Plate 21, Fig. 6; Plate 22, Fig. 1. 



Biapiosis. Body may appear as a flattened plate-like mass, perforated by spaces which 

 pass through from one surface to the other ; or as an amorphous mass excavated by spaces 

 which pass through the body in several planes, and divide it into a number of anastomos- 

 ing lobes. Color ashy gray. Sponge firm and of cartilaginous consistency. Upper 



and lower surfaces differentiated. Upper surface roughened with closely set minute 

 projections which reach 1 mm. in height, and consist of, or are supported by, tufts of 

 spicules projecting from the dermal reticulum. Under surface as compared with the 



