HALICHONDRIA. 139 



granular, not netted : spicula obtuse at one end, and tapered to 

 a sharp point at the opposite one, rather short, but variable both 

 in length and thickness. 



The specimen fi-om which our figiu'e is taken owes its pear- 

 shape to the form of the piece of shell which it has entirely en- 

 crusted. I owe the opportunity of examining it to the attention 

 of William Thompson, Esq. of Belfast, — a naturalist ever on 

 the watch to contribute to others whatever his zeal has collect- 

 ed together ; and whose uncommon tact in the discrimination 

 of species renders his aid and opinion especially valuable. 



31. H. SUBEREA, encrusting dead univalve shells ; structure 

 medullary, compact, the surface even, porous, icithout fecal 

 orifices ', spicula fusiform and slightly curved. 



Plate XII. Fig. 5, 6. 



Spongia suberia, Montagu in Wern, Mem. ii. 100, 



Sp. suberosa, Gray's Br. PI, 361. 



Halichondria suberica, Flem. Brit. Anim. 322. Coldstream in 



Edin. New Phil. Journ. ix. 235, pi. 2, fig. 3-5. Thompson in 



Ann. Nat. Hist. v. 254. Bellamy's South Devon, 268. 

 Halispongia suberica, Blainv. Actinol. 532. 

 Alcyonium bulbosum, Esper, Alcyon. p. 41, tab. 12, fig. 1-6. 

 Alcyoniura tuberosum, Esper, Alcyon. tab. 13, fig. 1-6. 

 Alcyonium compactum. Lam. Anim. s. Vert. ii. 400 : 2d edit. ii. 



606. Lamour. Cor. Flex. 354. Corall. 251. Parkins. Oryc- 



tol. 59. 



Hah. Not imcommon in the estuary of Kingsbridgc, and is 

 frequently taken by the dredgers on the coast of Devonshire, 

 Montagu. At Scarborough, Mr Bean. Rothesay Bay, Dr 

 Coldstream. Coldingham, Berwickshire, Mr Maclaren. " I 

 have found this species encrusting corallines in the Frith of 

 Forth," Dr Fleming. Ayrshire, Rev. D. Lnndshorough. 

 Isle of Man, E. Forbes. Dredged in the loughs of Strangford 



