KiKK. — Spo)ificK coUectcd (it the Kcrmcuhc hJniuh. 579 



A Clathrioid sponge in Mr. Oliver's collection has both smooth and 

 sjiined echinating styli. I think it best to interpret the generic character 

 as to echination to mean that there must be spined echinating styli and 

 that there may be smooth echinating styli as well, rather than to establish a 

 new genus for this sponge. 



Clathria intermedia n. sp. Fig. 5. 



Sponge massive, encrusting, harsh to the touch. On the upper surface 

 are numerous low, conical elevations, each terminating in a circular osculum, 

 which is about 3 mm. in diameter. 



The single specimen is 5 cm. long, 1-5 cm. high. Colour brownish- 

 grey. 



Skeleton showing primary and secondary fibres. The former generally 

 radiate from the walls of the gastral cavity to the surface ; the latter connect 

 the primary fibres, giving approximately right-angled meshes. Colour in 

 balsam light amber. The primary fibres are cored by a strand of smooth 

 styli, the strand being from 1 to 4 spicules thick. The apex of the spicules 

 is nearly always directed towards the surface of the sponge, where one or 

 two of these smooth styli may project from the end of the primary fibres. 

 Secondary fibres seldom contain spicules. Both primary and secondary 

 fibres are echinatcd sparsely by smooth and by spined styli in about equal 

 numbers. Only the base of the echinating spicule is imbedded in the 

 sjiongin, and the spicules project at almost right angles to the fibre. There 

 is no special dermal skeleton. The sponge-flesh contains abundant smooth 

 styli showing no definite arrangement. 



Spicules : Megascleres all styli. (1.) The most characteristic are fairly 

 stout spicules with well-rounded base, the broadest part of the spicule being 

 about one-third of the length from the base. These spicules usually run ab- 

 ruptly to a sharp point. Size, 0-1 mm. by 0-009 mm. The smooth echinating 

 spicules are all of this kind, as are most of these that core the fibres or that 

 lie loose in the sponge-flesh. In the latter position the styles may be blunt, 

 and there are long and slender styli. The most slender have a thickness 

 of about 0-001 mm., and these may be variously curved. (2.) Spined styles 

 occurring as echinating spicules only ; somewhat tylote, spines irregu- 

 larly scattered, directed straight outwards. The spicule tapers to a fairly 

 sharp point. The apical portion of the spicule — about one-sixth of the 

 whole length — is the only part that is always free from spines. Microscleres 

 — (1) Isochelae, palmate. As the spicule lies on its side it presents a distinct 

 indentation on the convex side ; this represents the shank of the spicule, 

 along which the palmate expansion does not extend. (2.) Simple sigmata, 

 somewhat larger than the isochelae. These are few in number. (3.) Toxa, 

 slender, sharp-pointed ; usually with a well-marked primary curve, and 

 feeble secondary curves. 



A single dry specimen. " Cast up on Denham Bay beach, Sunday 

 Island ; 27/7/08." 



Genus Clathriodendron Lendenfeld (V, p. 215). 



" Desmacidionidae with exceedingly large tylostylote megasclera. The 

 spongin fibres of the supporting skeleton contain only few spicules. Echi- 

 nating spicules spined styli." 



19* 



