310 A MONOGRAPH OF THE 



The form of this sponge is an irregular series of con- 

 fused short, stout, and somewhat compressed inosculating 

 branches, elevated on a short pedicel. The entire height 

 slightly exceeds three inches, and the extreme lateral ex- 

 tension is very nearly equal to the height. The true base 

 of the sponge is not preserved, and the present base has 

 been rounded off by the action of the sea. The oscula are 

 few in number, and are more frequently situated on the 

 edges than on the expanded portions of the branches ; the 

 largest does not exceed a line and a half in diameter. The 

 largest of the pores are barely visible to the unassisted eye, 

 but by the aid of a lens of two inches focus, they are very 

 apparent. The unispiculous network of the dermal mem- 

 brane is a very beautiful object ; the spicula of which it is 

 composed are of the same form and of very nearly the same 

 proportions as those of the skeleton, the only difference 

 being, that the greater portion of them are scarcely as 

 stout. The interstitial membranes are very pellucid, and, 

 in the specimen under consideration, are not very abun- 

 dantly furnished with sarcode ; but as the sponge has been 

 much worn by the action of the sea previously to being 

 taken, it is probable that much of the sarcode may have 

 been washed out of it. The spicula of the interstitial mem- 

 branes are few in number, and of the same form as those 

 of the skeleton, but shorter and much more slender in 

 their proportions. 



The sponge was brought up by the trawl about a mile 

 off Hastings, nearly opposite to the Castle Hill. 



A full- sized skeleton spiculum measured 5 ^th inch in 

 length. A second specimen, for which I am indebted to 

 Dr. G. B. Turner, of Hastings, who found it on the beach 

 opposite St. Leonard's, has the branches more decidedly 

 compressed than the first one, and the oscula are from one 

 tenth to one eighth of an inch in diameter. The sponge is 

 of the same height as the first one, but much less complex 

 in its mode of branching, and the mode of the exterior of 

 the sponge in this specimen appears to be by regular bi- 

 furcations. 



