Zoology.] NATURAL HISTORY OF VICTORIA. \Polyzoa. 



This species occurs in small purplish patches on algae at 

 Queenscliff. 



Explanation of Figures. 



Plate 25. — Fig. 4, specimen, natural size. Fig. 4a, same, highly magnified, showing the 

 form and arrangement of the cells, aperture, and spines, with one avicularium near middle of 

 lower part of figure. 



Plate 25, Figs. 5, 6. 



MEMBRANIPOKA UMBONATA (Busk). 



Description. — Cells irregularly oblong or elliptical ; margins scarcely raised ; 

 mouth arched above, straight below, frequently contracted about the middle, giving 

 it a trifoliate appearance ; a spine on either side. An avicularium on the summit 

 of a thick cylindrical process on the front of each cell. Ovicell rounded or 

 elongated, encroaching on the cell above. 



Reference.— Busk, Cat. Mar. Pol. Brit. Mus., p. 57, t. lxxiii., f. 6, 7. 



Distinguished at once by the peculiar avicularium on the front 

 of the cell, which is well shown in Fig. 6a. 

 On algae, Queenscliff. 



Explanation of Figures. 



Plate 25. — Fig. 5, portion, natural size. Fig. 5a, same, magnified. Fig. 56, ayicularium, 

 magnified. Fig. 6, another specimen, natural size. Fig. 6a, same, highly magnified. 



Plate 25, Fig. 7. 

 MEMBKANIPOKA PILOSA (Linn. sp.). 



Description. — Cells elongated, narrow inferiorly, lower half filled in by a 

 calcareous punctate expansion; margins of the opening bearing several (usually 

 three on each side) short, pointed spines ; a very long articulated vibraculum 

 situated on the calcareous expansion immediately beneath the open part of the cell ; 

 mouth small, lunate. 



Reference. — Flustra pilosa (Linn.) Systema, 1301 ; Busk, Cat. Mar. Pol. Brit. 

 Mus., p. 56, t. lxxi. 



This, one of the most beautiful species of the genus, may at 

 once be distinguished by the cribriform, calcareous lamina, and the 

 long articulated vibraculum, which is usually so large as to be 



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