Zoology.-] NATUEAL HISTORY OF VICTORIA. \Polyzoa. 



of the cell, not, as in the latter, extending upwards beyond the 

 level of the mouth, and by the wart-like elevation which is 

 especially marked in incinerated specimens. 



Explanation op Figures. 



Fig. 1, specimen, natural size. Fig. la, group of cells, magnified. Fig. lb, margin of 

 fenestra, magnified. Fig. lc. three cells, more highly magnified. Fig. Id, two cells, to show the 

 pattern after incineration. Fig. le, two cells of D. cellulosa, similarly treated. 



Plate 66, Fig. 2. 



DICTYOPORA ALBIDA (Kirchenpauer). 



Var. avicularis (P. McGil.). 



Description. — Polyzoary expanded, proliferous and cavernous; fenestra 

 regular, nearly circular, margin forming a continuous punctate rim j cells expanded 

 and arched above, narrowed below, surface pitted, the pits forming a regular row 

 just inside the margin ; surface raised round the mouth, which is nearly circular ; a 

 round pore a short distance below, to the side of which is frequently attached a 

 minute, triangular avicularium, with the mandible pointed obliquely upwards ; 

 several large avicularia, replacing cells, situated round the margins of the fenestra. 



Reference. — P. H. MacGillivray, Trans. Roy. Soc. Vict., 1881. 



Port Phillip Heads, first found by Mr. J. B. Wilson. 



This, I believe, to be a form of Dr. Kirchenpauer's D. albida. 

 It attains a very large size, one specimen, dredged in 15 fathoms, 

 measuring over 30 inches in circumference. The plate is proliferous, 

 and united in various ways so as to form chambers or caverns like 

 those of D. cellulosa, but usually of larger size. On one specimen 

 a broad, white, irregular rib extends up the plate. The color is 

 ash-grey ; the margins of the fenestra? white. The fenestra? are 

 about 2mm in diameter, and the interspaces about 3mm wide. 

 The cells resemble those of D. Wilsoni, but they are broader and 

 more regularly trapezoid ; the special pore is also smaller, the 

 surface is not so much raised on each side, and the puncturation is 

 deeper and larger. These characters are more prominently shown 



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