MARINE POLYZOA. 5V 



Flustra Peachii, Couch, Rep. Cornw. Polytechnic Soc. 81 (see 



Johnst. Brit. Zooph. 478). 



Amphiblestrum membranaceum, Gray, List B. R. 110. 

 Hab. European Seas ; Australia ? : on stones and shells. 



The above synonyms are assigned to this species chiefly on 

 the authority of Dr. Johnston, but several of them are probably 

 erroneous. No species presents greater diversities of form than 

 the present ; and specimens will occasionally be met with, espe- 

 cially from deep water, in which, from the almost entire absence 

 of the spines and avicularia, great difficulty will be experienced 

 in the determination; careful inspection, however, of various 

 parts of the patch, especially at the growing edge, if it be in the 

 growing state, will usually suffice to trace its relationship to the 

 form assumed as the type of the species. The figures given in 

 the different plates referred to, afford but a faint notion of the 

 endless varieties induced by age, wear and situation, particularly 

 as to depth, of this protean form. I have ventured to assign a 

 new term to it, because the specific name * membranacea ' belongs, 

 as I think, of priority, to another species; and Dr. Fleming's 

 name, * unicornis,' is so inapplicable that its retention seems 

 scarcely justifiable. 



7. MEMBRANIPORA ROZIERI. PI. LXV. fig. 6. 



Front of cell elliptical ; mouth orbicular, with a raised margin 

 and small tuberosity on each side ; an oval or elongated opening 

 on each side of the front of the cell immediately below the mouth. 

 Ovicell globose, carinate in front. 



Flustra Rozieri, Audouin, Savigny, Egypt, pi. 8. fig. 9. 

 Hab. Rio de Janeiro, Darwin. On fucus. 



Notwithstanding the above habitat, from which only have I 

 seen a specimen, collected by Mr. Darwin, there can be no doubt 

 of the identity of the form with that so beautifully figured by 

 Savigny. 



8. MEMBRANIPORA ROSSELII. PI. C. fig. 2. 



Front of cells oval, wide, or elongated ; the lower half of the 

 area filled in by a calcareous granulated expansion ; margin finely 

 beaded. Ovicell flattened in front. 



Flustra Rosselii, Audouin, Expl. 240; Savigny, Egypt, pi. 10. 



fig. 11. 

 Hab. Orkney. Coast of Devon (Start) ?, Eowerbank. Bay of 



Gibraltar, M' Andrew, Landsborough. 



