90 Froceeclin<i6 of the Royal Society of Victoria. 



less. These spicules are imbedded in large numbers in the 

 dermal cortex at various levels ; they mostly lie more or 

 less parallel to the long axis of the sponge, but there is a 

 good deal of irregularity in their arrangement and not 

 infrequentl}" one end of the spicule projects slightlj'- beyond 

 the dermal surface. (7) Minute oxea of the dermal surface ; 

 short and slender, usually slightly curved ; the inner end 

 gradually tapering to a fine point, the outer end thicker, 

 more or less hastate, minutely toothed or roughened. These 

 spicules measure only about 004 by 0'003 mm.; they occur 

 in large numbers on the dermal surface. (S) Minute oxea 

 of tlie gastral surface ; similar to the foregoing but not so 

 numerous. 



One of the two specimens in the collection was attached 

 to a crab's back, which it completely covered like a thick 

 crust ; it resembled a specimen cut in half longitudinally, 

 with the concave gastral surface turned towards the crab's 

 back. Hence, as the gastral cavity was no longer an 

 enclosed space, there was no oscuium in the ordinary sense 

 of the word. The crab, of course, occupied the gastral 

 cavity, and the exhalant canals of the flagellated chambers 

 must have discharged their contents on to the crab's back. 

 One often finds sponges growing on crab's backs, but I 

 never before saw a case in which the essential torm of the 

 sponge was so strangely modified in accordance with this 

 habit. Had it not been for the presence of the other and 

 normal specimen in the collection I should have been inclined 

 to regard this strange modification in form as of at least 

 specific value. The species, is, however, so well characterised 

 by spiculation, &c., that there can be no doubt as to the 

 identity of the two specimens. 



I have much pleasure in dedicating this remarkable species 

 to Professor W. Baldwin Spencer. 



Locality. — Watson's Bay, Port Jackson (coll.T. Whitelegge). 



27. Synute pulchella, Dendy. 



Synute 'pulchella, Dendy. Proceedings of the Royal 

 Society of Victoria, Vol. IV (New Series), p. 1. 



I have nothing to add to my description of this remark- 

 able sponge until such time as I ma}^ be able to publish 

 illustrations of its anatomy. 



Locality. — Near Port Phillip Heads (Dendy). 



