BRITISH SPONGIAD^E. 311 



25. Isodictya palm at A, Bowerbank. 



Haxtchondria palmata, Johnston. 



Sponge. Sessile or slightly pedicelled, arborescent or pal- 

 mate and digitate, compressed. Surface even. Os- 

 cula simple, or margins slightly elevated. Pores in- 

 conspicuous. Dermal membrane pellucid, spiculous ; 

 tension spicula same as those of the skeleton, irregu- 

 larly dispersed, few in number ; and equi-anchorate 

 retentive spicula with bifurcate terminations, with ex- 

 flected points ; irregularly dispersed, very numerous. 

 Skeleton. Open and diffuse ; primary and secondary 

 lines multispiculous, rete more than the length of one 

 spiculum in width ; spicula acerate, stout, and rather 

 short. Interstitial membranes. Tension spicula same 

 as those of the skeleton j retentive spicula same as 

 in the dermal membrane, irregularly dispersed, ex- 

 ceedingly numerous. 



Colour. Dark red brown in the dried state, or light 

 gray. 



Habitat. Coasts of Northumberland and Scotland, Mr. 

 Alder and Mr. Peach. Orkney Islands, Mr. McAndrew. 



Examined. In the dried state. 



This sponge is, I believe, the Mermaid's glove of the 

 Orkney fishermen. I received a fine specimen from Mr. 

 McAndrew in 1851. It is thirteen inches in height, and 

 about nine inches at its greatest width ; it is palmate, and 

 has a rude resemblance to a glove. This is the only case 

 in which I have seen it assume this form. It usually con- 

 sists of a number of stout, irregular, and somewhat com- 

 pressed branches, and is frequently a foot in height. There 

 are two fine specimens of this description in the Newcastle 

 Museum; the finest of the two was found by Mr. Alder, 

 at Holy Island, and the second one by Mr. W. J. Foster, 



