468 " THETIS " SCIENTIFIC RESULTS. 



The primary fibres consist of compact bundles of spicules 

 imbedded in a moderate amount of pale spongin ; usually they are 

 about O'l mm. in diameter ; the secondaries are multispicular, 

 and measure from 0-05 to 0'07 mm.; the connecting fibres and 

 those of the surface are slender, with two or three spicules in a 

 row, and vary from 0'02 to 0'04 mm. in thickness. Mesh rather 

 open, either oblong or subrectangular, and usually about 0'5 to 

 O'S mm. in width. 



Megascleres : — straight, styli cylindrical to within about 2 

 diameters of the not very acute extremity; size 0'2 by 0-0075 mm. 



Microscleres: — palmate anisochelpe, 0*032 mm. long and 0-01 mm. 

 wide ; the lateral processes at both ends of the spicule are well 

 developed, and generally they closely resemble the anisochelje of 

 Esperella lapidiformis, Ridley and Dendy.*' One example 

 obtained off Coogee, 49-50 fathoms. 



ESPERELLA TEXTILIS, sp. nov. 



(Plate xliii., fig. 2). 



Station 44. 



The single example forms a subflabellate expansion 200 mm. 

 high and 120 mm. wide, and from 30 mm. to 40 mm. in thickness. 

 The sponge consists of a very open network of densely spicular 

 fibres, with little obvious spongin ; the primaries give off a series 

 of secondaries at pretty regular intervals of about 5 mm., these 

 are united here and there with the somewhat irregularly disposed 

 connecting fibres ; the whole forming a loosely arranged network, 

 the mesh of which is usually square or slightly oblong. The 

 dermal surface presents a beautiful appearance to the unaided 

 eye, like that of some delicate network or textile fabric. The 

 specimen is a dried one and does not exhibit anything definite in 

 the way of distinct pores or oscula. The main fibres consist of 

 compactly-arranged spicules, and vary from 0"5 to 1 mm. in 

 diameter ; the branches are about 0-25 mm., and the dermal 

 and connecting fibres range from 0*05 to 0"1 mm., whilst some of 

 the finer cross fibres consist of one or two spicules in a row. 

 The texture of the specimen is rather brittle and the colour white 

 or grey. 



Megascleres: — subtylostyli, with fusiform shaft, acutely pointed 

 at the base and evenly rounded at the apex, with a perceptible- 

 constriction about two diameters below the summit. Size 0*55 mm, 

 by 0-01 to 0-014 mm. 



* Ridley and Dendy— Chall. Rep., Zool., xx., 1887, pi. xv., fig. 10-lOa. 



