328 POLYZOA INFUNDIBULATA. 



ish, porous, hairy : cells short, somewhat tiibulous, with large round- 

 ish apertures ossified and toothed on the margin, the teeth short 

 sharp, and rigid, and behind the mouth of each cell there is a very 

 ong tubular bristle which issues from a hollow base like a hair from 

 its bulb. — Polypes with twelve tentacula, long in proportion to the 

 body, thick and rather clumsy. Farre. " Polypus — tentacula cir- 

 liter viginti, asqualia et corpus fequantia, in campanos formam ex- 

 pandit." Pallas. 



When the polypidom encrusts the broad-leaved fuci or shells the 

 texture is thinner and the cells more completely developed, and then 

 their surface is perceived to be finely frosted, or rather specked with 

 numerous translucid granules. The small spines of the aperture are 

 omitted in the figure of Ellis ; and that referred to for the variety 

 dentata is imperfect and unfinished. Many believe this variety to 

 be distinct in species, and specimens, sufiiciently characteristic, can 

 easily be produced in favour of the opinion, which, however, I am 

 satisfied is erroneous. 



M. pilosa often rises into small sponge-like fronds, cellular and 

 hirsute on each side. " In frondes lubenter assurgit, utrinque cellu- 

 losas crassiusculas, spongiosas ; primo simplices, lineares, obtusas • 

 deinde ramosas ; imo pinnato-multifidas fere nunquam pollice lon- 

 giores." Pallas. 



2. M. MEMBRANACEA, " ccUs ovatc OT subquaclraTigular, with 

 a Hunt hoUoiv conical process at the summit of each.'''' Fleming. 



Plate LVI. Fig. 7. 



Flustra membranacea. Mull. Zool. Dan. prod. 253, no. S054. Zool. Dan. iii. 63, tab. 

 117, fig. 1,2. Fabric. Faun. Groenl. 437. Xawci;/;-. Corall. 47.— Flustra nni- 

 comis, Fhmhuj in Edin. Phil. Journ. ii. 87. Flem. Brit. Anim. 236. Blainv. 

 Actinolog. 450. Johnston in Trans. Newc. Soc. ii. 266. — Membranipora unicornis, 

 Blainv. lib. cit. 447. — Flustra tuberculata, Johns. Brit. Zooph. 289. Bosc ? Vers. 

 iii. 143. 



ffab. " Common, especially on stones, near low-water mark," 

 Fleming. I have never seen it on sea-weed. 



Polypidom in the form of a thin closely-adherent, greyish-white 

 subcalcareous crust, reticulated like a piece of gauze to the naked 

 eye, spreading circularly : cells quincunxial, short, with a large ovate 

 or subquadi-angular aperture, the margin of which is slightly thick- 

 ened, and usually unarmed ; but in the space between the cells, and 

 above the aperture, there is a stout hollow conical process, mostly 



