BRITISH SPONGIAD.'E. 195 



Dr. Johnston believed that this species was identical with 

 Lamarck's Spongia virgultosa, but I regret that I cannot agree 

 with him in that opinion. The learned author of the ' History 

 of the British Sponges' states that he had seen only frag- 

 ments of the species from the collection of Mr. Bean, and 

 I feel satisfied that had he seen Mr. Bean's type sponge, and 

 had obtained five specimens of the same species as I have, he 

 would have entertained a different opinion on the subject. 

 The species described by Lamarck in the second edition 

 of ' Anim. s. Vert.,' page 565, is characterised as follows : 

 " 8. stipite duro, erecto, ramoso ; ramis subteribus, virgatis 

 erectis, acutius cults ; superjicie pa?t>/ca ;" and Lamarck 

 then refers to Esper, Suppl. 2, table 66, than which 

 nothing can well be more unlike to our sponge. 



Nor does Lamarck's description at all agree with the 

 British specimen, which has no stem, and no appearance of 

 branches, and has no tendency to terminate acutely. On the 

 contrary, the distal end is usually rather broader than the 

 proximal one, and the surface of all the specimens I have 

 seen are quite smooth, instead of being ragged, as Lamarck's 

 sponge is said to be. Esper's figure, without reference to 

 anatomical characters, will serve to represent numerous other 

 similarly ramose species beside the one for which it was 

 originally designed, and the same may be said of Lamarck's 

 description, based entirely on external characters. I have, 

 therefore, thought it advisable to retain the specific name 

 Virgultosa for the British species, as established by Dr, 

 Johnston. 



27.Hymeniacidon plumosa, Bowerbank. 



Spongia plumosa, Montagu. 

 Haliciiondeia plumosa, Johnston. 



Sponge. Sessile, upper surface rugose and mammillated. 

 Dermal membrane pellucid, furnished with flat fasci- 

 culi of large acerate spicula ; and minute dentato- 

 palmate angulated anchorate, retentive spicula ; occa- 

 sionally arranged in circular groups, and attached by 



