REPORT ON THE MONAXONIDA 53 



arrangement, running towards the surface, where they break up into divergent tufts of 

 slender bicapitate cylindrical spicules (tylota). 



Sincules. — (a) Megasdera; (1) long, slender, slightly curved, hastately pointed styli ; 

 measuring about 0'3 by 0"0042 mm. These spicules may approach the tylostylote form 

 (PI. XXIII. figs. 9, 9a) ; (2) long, slender tylota, with usually only slightly developed, 

 oval heads; size about 0'35 by 0-004 mm. (PI. XXIII. figs. 96, 9c). {b) Mkrosclera ; 

 exceedingly fine, hair-like, scattered rhaphides, about 0"13 mm. long. 



This species is represented in the collection by a thick triangular lump with square- 

 cut edges, which appear to be natural ; the upper surface is almost flat. The sponge, 

 especially near the lower surface, contains large quantities of foreign bodies, sand, 

 fragments of shells, &c. It is quite possible that here, as in other cases, the foreign 

 bodies to a certain extent replace the proper skeleton of the sponge. The species is 

 characterised by the presence of these foreign bodies, whence the specific name, and by 

 the proportions of the megasclera and rhaphides, but it comes near to Tedania 

 temdcapitata, being distinguished from it chiefly by the rhaphides being only about 

 half as long as in that species, and by the presence of the foreign bodies ; hence it may 

 perhaps have to be united with it at some future time. 



Locality.— Station 162, April 2, 1874 ; lat. 39° 10' 30" S., long. 146" 37' 0" E.; Bass 

 Strait ; depth, 38 fathoms ; bottom, sand and shells. 



Tedania massa, Ridley and Dendy (PL XL figs. 4, 4a ; PI. XXIII. figs. 2, 2a, 26). 

 1886. Tedania massa, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. p. 335. 



Sponge (PI. XI. fig. 4) massive, flattened and cake-like, amorphous or lobose. Size 

 apparently indefinitely great, the largest specimen measuring as much as 325 mm. long by 

 200 broad, and from 12 to 25 mm. thick ; other specimens are as much as 50 mm. thick. 

 Colour in spirit, grey, brown, or pale yellow. Texture very soft and spongy. Surface 

 fairly even, very minutely hispid. Dermal membrane fairly distinct, with a reticulate 

 appearance. Oscida more or less numerous, scattered, or in rows along the margins of 

 the flattened lobes (PL XL fig. 4, o), flush with the surface or with slightly raised margins ; 

 diameter about 4 mm. Pores scattered, but commonly in groups (PL XL fig. 4a). 



Skeleton. — Divisible into three parts : — ( 1 ) a very loose, isodictyal reticulation of large, 

 stout, stylote spicules. (2) A loose reticulation, with very large meshes, of stout, compact 

 fibres like bands of horse-hair, composed of very long, fine, flexible, oxeote rhaphides, 

 with more or less admixture of the stylote and diactinal spicules. One can distinguish 

 primary fibres running more or less vertically to the surftice, and secondary fibres crossing 

 these at right angles ; but the arrangement is very irregular and the fibres run for long 

 distances without being crossed by others. (3) On approaching the surface of the sponge 

 both these kinds of skeleton give place to a reticulation of hastately pointed cylintbicals 



