Zoology.'] NATURAL HISTORY OF VICTOEIA. [Polyzoa. 



PLATES 25 AND 26. 



Plate 25, Fig. 1. 



MEMBRANIPORA MEMBRANACEA (Lnw. sp.)- 



[Genus MEMBRANIPORA (Blainrille). (Sub-kingd. Mollusca. Class Polyzoa. Order 

 Infundibulata. Sub-Order Cheilostomata. Fam. Membraniporidse.) 



Gen. Char. — Polyzoary spreading, encrusting or occasionally suberect. Cells contiguous, 

 irregular, quincuncial or in transverse and longitudinal series, separated by raised margins, 

 front more or less membranous.] 



Description. — Cells oblong-, much longer than broad, straight or slightly 

 rounded above, straight below, separated by raised margins ; a short, blunt spine at 

 either angle superiorly. Front entirely occupied by a thin membrane. 



Reference. — Flustra membranacea (Linn.) Systema, 1301 ; Busk, Cat. Mar. 

 Pol. Brit. Mus., p. 56, t. Ixviii., f. 2. 



The cells are of large size, 2 to 3 times as long as broad, nearly 

 rectangular, and separated by prominent smooth, or slightly crenu- 

 lated margins. They are an-anged in lines, which frequently 

 bifurcate and radiate, so as to give the whole coencecium a rounded 

 or semilunar form. 



Of frequent occurrence everywhere on our shores, creeping over 

 broad seaweeds, on which it occasionally forms lace-like patches 

 several inches in diameter. 



Explanation of Fioubes. 



FtATE 25. — Fig. 1, specimen, natural size. Fig. la, same, magnified. Fig. lb, cells, more 

 highly magnified. 



Plate 25, Fig. 2. 



MEMBRANIPORA PERFORATA (P. MacGil.). 



Description. — Cells very irregular in shape, generally obscurely hexagonal or 

 P3rriform ; mouth narrow, with slightly thickened lips, and a stout spine at either 

 side superiorly 5 front of cell minutely cribriform, with a large round opening on 

 either side, close to the margin. Ovicell large, galeate, widely open beneath, 

 granular. Avicularium usually at the base of a cell, mandible triangular, acute. 



Reference. — P. MacGillivray, Trans. Phil. Instit. Vict., 1859. 



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