132 BRITISH SPONGIAD^. 



to me by Dr. Bowerbank labelled " Isodicty a jugosa ? 

 (N.). 



36. ISODICTYA PALMATA (Johnston), n, 311; in, PL LII. 



1861 Haliclona palmata, Bow. List Brit. Marine Invert. 

 Fauna (Brit. Assoc.), p. 71. 



Habitat. This is one of the finest of British 

 sponges, and very large specimens are occasionally 

 brought up attached to the hooks of the " long lines ' 

 set by the fishermen of Holy Island, Northumberland 



37. ISODICTYA TBUNCA, Bow. 9 n. sp., iv, Plate XI, figs. 

 510. 



" Sponge massive, sessile. Surface even, smooth. 

 Oscula simple, dispersed. Pores inconspicuous, appa- 

 rently congregated in aspiculous areas. Dermal 

 membrane abundantly spiculous ; spicula irregularly 

 dispersed, acerate, slender. Skeleton symmetrical; 

 primary lines multispiculous, irregular in number of 

 spicula, rarely more than one spiculum wide ; second- 

 ary lines unispiculous, occasionally bi- or trispiculous; 

 spicula subfusiformi-acerate, short, and rather stout. 

 Interstitial membranes furnished abundantly but irre- 

 gularly with slender, acerate, tension spicula, same as 

 those of the dermal membrane. Internal defensive 

 spicula attenuato-acuate, very minute, with more or 

 less truncated bases, which are incipiently spinous. 



" Colour. In the dried state, externally, dark purple ; 

 internally, nut-brown. 



