Zoology. - ] NATURAL HISTORY OF VICTORIA. \_Po/,,zoa. 



Very conspicuous from the highly porcellaneous character of 

 the zocecia with their polished convexities. At the growing 

 extremity of one specimen the zocecia spread irregularly in the 

 manner of P. catenularia. I have little doubt that this is the 

 species described by Lamouroux as Cellipora alata. 



Explanation of Figure. 

 Plate 106. — Fig. 6, small portion of specimen, magnified. 



Plate 106, Fig. 7. 



ELECTRA FLAGELLUM (McG.). 



[Genus ELECTRA (Lamx.). (Sub-king. Mollusca. Class Polyzoa. Order Infundibulata. 

 Sub-order Cheilostomata. Earn. Membraniporidae.) 



Gen. Char. — Zoarium encrusting or filiform and erect. Zocecia elongated, narrowed 

 below, closely adherent together ; lower part convex without distinct raised margins, perforated 

 by numerous small foramina ; aperture occupying the whole width of the zocecium above, deep, 

 with thick raised margins ; one or more very large whip-like spines (occasionally replaced by 

 an avicularium) below the margin of the aperture and a variable number of small sharp spines 

 on its circumference.] 



Description. — Zocecia arranged in regular transverse series, elongate-quadrate; 

 aperture occupying the whole width of the zocecium above, its edge very prominent 

 and thus causing the corresponding parts of the zocecia to be separated by much- 

 raised margins ; lower part of zocecium convex, surface closely pitted and extending 

 a little further up one side than the other; a stout conical spine superiorly on each 

 side ; an enormous whip-like spine below the aperture to one side, and one or 

 occasionally two small spines on the margin on the other side. 



Reference. — Membranipora flagellum, P. H. MacGillivray, Trans. Roy. Soc. 

 Vict., Dec. 1881. 



QueensclifF, on stems of Cymodocea antarctica. 



The only species with which this can be confounded is E. pilosa, 

 from which it differs in the arrangement of the zoaicia in regular 

 transverse series, in the lower part being produced more up one 

 side of the aperture, and in the long spine being to one side. The 

 oral opening is situated very deeply. The upper margin of the 

 zocecium forms a deep arched vault against the base of that above, 

 and is surrounded by a continuation of the thickened rim of the 

 aperture. All my specimens present the same arrangement, which 

 is also slightly seen in some specimens of E. pilosa. It is possibly 

 ocecial, and may consequently not be constant. 



Vol. II.— Decade XI.— e. " 25 \ 



