I 



SPOXGIIDA. 381 



excretory chambers, separated by comparatively narrow and sheet- 

 like skeletal trabecular, with even surfaces, which distinguish Hip- 

 pospongia; hut on looking at the brief description given by Prof. F. 

 E. Schulze (Zeitsch. wiss. Zool. xxxii. p. 620) of the Adriatic form 

 which he has placed under Euspongia officinalis, as var. tubulosa, 

 I saw that he had had a closely similar form before him. It agrees 

 witli our specimen in the long tubes (of much less diameter, how- 

 ever, in the Adriatic tubulosa than here) and in the absence of sand- 

 cored fibres; but it appears to want the following striking peculi- 

 arities of our form: — (1 ) subglobular form (incrusting in Schulze's 

 specimens): (2) trabecular structure of main body; {'■'>) absence of 

 conuli (they are stated by Schul/.e to occur on the general body of 

 the sponge, but in a very well-preserved specimen in absolute alcohol 

 which he has liberally presented to the National Collection, I find 

 them only on some small digitate lobes which spring from the body ; 

 those possibly occurring upon one of the tubes in var. cavernosa are 

 evidently only exceptional) ; (4) approximate equality in stoutness 

 of fibres throughout (in var. tubulosa those near the surface are 

 said to be thinner than elsewhere). 



In a preparation made from Prof. Schulze's specimen I do not 

 notice a special thinness of the fibres at the surface, but they seem 

 to have a slightly greater diameter throughout than in our form. 



Considering the dry state of this single specimen and the evident 

 plasticity of form in E. officinalis, I think it best to associate this 

 form provisionally with that termed by Prof. Schulze var. tubulosa, 

 feeling that it may be only a mere extreme variation of the species 

 in the same direction as that variety, deferring (as I feel bound to 

 do on a question which Prof. Schulze has made so eminentl} r his 

 own) to Prof. Schulze's judgment in specifically uniting aberrant 

 forms like these with those familiarly known as E. officinalis ; I am, 

 however, induced, from the points of divergence from tubulosa noted 

 above, to assign to it a distinct varietal designation. 



Hah. Torres Straits, 10 fms. 



Distribution (of species). Mediterranean {Schulze, &c). 



4. Euspongia septosa. 

 ? Sponjyia septosa, Lamarck, Ann. Mus. Hist. Nat. xx. p. 373. 



It is possible that Lamarck's species, of which I have access to 

 the description only, is a Dendrospongia (Hyatt), as its somewhat 

 honeycomb-like surface renders not impossible ; but it seems to 

 resemble a species in this collection, represented by two small speci- 

 mens in spirit, of a dark grey colour, each attached to two or more 

 stones, over which they form horizontally expanded laminae which 

 rise into subcylindrical lobes 5 to 7 millim. in diameter. The surface 

 is broken up by a number of sharp prominent ridges and points 

 1 to 3 millim. high ; the intermediate surface is rough. Primarv 

 skeleton-fibres set approximately at right angles to surface, thickness 

 about '06 millim. ; secondaries approximately vertical to primaries, 

 about "035 to "053 millim. in thickness, forming with some connecting 



