132 BRITISH SPONGIAD^. 



to me by Dr. Bowerbank labelled " Isodictya jugosa ? " 

 (N.). 



36. IsomcTYA PALMATA (Johnston), II, 311 ; iii, PI. LII. 



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

 Fauna (Brit. Assoc), p. 71. 



Habitat. — This is one of tbe 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 

 (N.). 



37. Isodictya trunca. Bow., n. sp., iv, Plate XI, figs. 

 5—10. 



" 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. 



" Coheir. — In the dried state, externally, dark purple ; 

 internally, nut-brown. 



