348 POLYZOA INFUNDIBITLATA. 



* * * Crustaceous. 



8. F. MEMBRANACEA, cells oblong, with a short blunt spine at 

 each corner. Ellis. 



PLATE LXVL FIG. 1, 2, 3. 



Flustra membranacea, Lin. Syst. 1301. Fabric. Faun. Groenl. 437. MM. Zool. 

 Dan. prod. 253. Ellis and Soland. Zooph. 18. Flem. Brit. Anim. 536. Johnston 

 in Trans. Newc. Soc. ii. 265. Blainv. Actinol. 450. Couch Zooph. Corn. 55 : 

 Corn. Faun. iii. 123, pi. 21, fig. 2. Fl. telacea, Lam. Anim. s. vert. 2de dit. ii. 

 223. Grant in loc. s. cit. iii. 1 1 1 . Membranipora membranacea, Blainv. Actinol. 

 447. 



Hob. On the fronds of the Laminarise and Fucoidese, common. 



Polypidom forming a gauze-like incrustation on the frond of the 

 sea-weed, spreading irregularly to the extent of several square inches, 

 in general thin and closely adherent, but sometimes becoming thick- 

 ish, and then capable of being detached in considerable portions ; cells 

 very obvious to the naked eye, oblong, quadrangular with a blunt 

 hollow spine at each angle. In many specimens there are some ano- 

 malous processes, a quarter of an inch in height, scattered over the 

 surface : they arise from within the cells, are simple, horny and tu- 

 bular, but closed at top. Ellis conjectured they were ovaries, and 

 the conjecture is rendered probable by the recent observations of Mr. 

 Couch. When the polypes are all protruded they form a beautiful 

 object under the microscope, from their numbers, their delicacy, the 

 regularity of their disposition, and the vivacity of their motions, 

 now expanding their tentacula into a beautiful campanulate figure, 

 now contracting the circle, and ever and anon retreating within the 

 shelter of their cells. The tentacula are numerous, filiform, white, 

 and in a single series. 



The Rev. David Landsborough has seen a specimen (and I have 

 seen its equal) of F. membranacea five feet in length by eight inches 

 in breadth. " As every little cell had been inhabited by a living 

 polype, by counting the cells on a square inch, I calculated that this 

 web of silvery lace had been the work and the habitation of above 

 two millions of industrious, and, we doubt not, happy inmates ; so 

 that this single colony on a submarine island was about equal in 

 number to the population of Scotland." Scott. Christ. Herald for 

 April 1840, p. 244. 



9. F. CORIACEA, cells broadly elliptical, coriaceous, with 



