.2 I 6 



••ENDEAVOUR" SCIENTIFIC EESULTS. 



fonn contiects the accessory with the prhicipal styVi. 

 Megascleres : — (/.) Smooth principal styli; maximum 

 size, joo X lo }i ; (ii.) acanthostyles, minutely spined, 

 seldom exceeding go x 6 p; {Hi.) auxiliary suhtylo styli; 

 maximum size, j8o x 6 p.. Microsclercs : — Flexuous liair- 

 Uke spicules {modified toxa)^ fairly abundant : maxi}nH)}i 

 length, at least 2^0 p. 



This species is represented in the collection 

 by a single dry \vashed-out specimen, of leaf- 

 like form. The lamina is elliptical in outline, 

 and measures 300 mm. in breadth, by 200 

 mm. in height ; the stalk is short, stout, and 

 proximally swollen. Both surfaces of the 

 lamina are elegantly ridged and furrowed, 

 over their entire extent, along lines which 

 radiate curvately from the junction of stalk 

 and lamina. The grooves are 2 to 5 mm. in 

 width; the intervening "ridges," which are 

 much compressed (septiform) and somewhat 

 jagged, measure i to 4 mm. in height. Be- 

 tween the ridges the lamina is comparatively 

 thin and, in the present condition of the 

 sponge, perforated by frequent rounded open- 

 ings up to 2 mm. in diameter. The consis- 

 tency is firm and tough ; the texture fibrous. 



The main skeleton is a close-meshed net- 

 work of strongly-developed horny fibres, the 

 stoutest of which attain a diameter of about 

 100 ft; the connecting fibres are free from 

 contained spicules. Echinating acanthostlyes 

 are scarce. In the central region of the 

 sponge, i.e., in the lamina proper, the reticula- 

 tion is irregular and confused ; intrafibraj 

 1 Tricbitoidal mi- spicules are here comparatively few in num- 

 crosclercs (modi- ^gr, and the distinction between main and 

 fied toxa). connecting fibres is often obscure. In the 



surface "ridges," on the other hand, the 

 main fibres run in close and fairly regular sub-parallelism, 

 and, owing to their contained spicules, stand out rather 

 conspicuously in comparison with the short aspiculous 

 transverse fibres. The fibral spicules, though almost 

 exclusively principal styli, may yet at times include a 

 considerable proportion of auxiliary tylostyli. Between 

 the fibres, more particularly in the central region of the 

 sponge-lamina, megascleres occur in great profusion ; they 

 consist chiefly of auxUiary spicules, which are often clustered 



Fig. 44— C. cosfi- 

 fera. a Principal 

 styles, b Auxili- 

 ary subtj'lostyle. 

 c Acantbostyles. 



