90 A MONOGRAPH OF THE 



same form spinulate, small., and slender; retentive 

 spicula attenuato-stellate, rather large, with few radii ; 

 and minute cylindro-stellate, radii numerous. Skeleton. 

 Fasciculi multispiculate ; spicula fusiformi-acerate, 

 stout. Connecting spicula attenuato-recurvo-patento- 

 ternate ; radii short, stout, and abruptly recurved near 

 their apices. External defensive spicula spinulate, 

 small, and slender, variable in size, and often flexuous. 

 Interstitial membranes abundantly supplied with the 

 same forms of stellate spicula as those of the dermal 

 membrane. 



Colour. Dried, dull ochreous yellow. 

 Habitat. Guernsey, Mrs. Buckland; Herm, Rev. A. 

 M. Norman. 



Examined. In the dried state. 



I received the sponge under consideration from my late 

 friend, Mrs. Buckland, who obtained it at Guernsey, with 

 other British species, in 1857. The specimen is not entire, 

 one end and a portion of one side having been cut away 

 for examination. From its present aspect it does not appear 

 to have exceeded an inch and a quarter in length by half 

 an inch in breadth, and the same in height ; and it seems 

 to have been adherent by nearly the whole of its under sur- 

 face. In its general aspect it closely resembles T. Collingsii. 



The dermis is very thick and dense, in consequence of 

 the profusion of the ternate terminations of the connecting 

 spicula which are crowded over each other, forming a dense 

 and strong crust to the sponge. The dermal membrane is 

 thin and pellucid, and is abundantly furnished with spinu- 

 late tension spicula irregularly dispersed on its surface, 

 iuterspersed with which there are both forms of the stellate 

 retentive spicula, but not in any great number ; while in 

 the membranes of the intermarginal cavities, and in the 

 interstitial membranes beneath, they are in profusion. The 

 intermarginal cavities are disposed between the dermal 

 membrane and the distal stratum of the ternate termina- 

 tions of the connecting spicula, the fasciculi of which diverge 



