Zoology.] NATUKAL HISTORY OF VICTORIA. [Polyzoa* 



Plate 45, Fig. 1. 



FLUSTRA DENTICULATA (Busk). 



[Genus FLUSTRA (Linn.). (Sub-kingd. Mollusca. Class Polyzoa. Order Infundibu- 

 lata. Sub-Order Cheilostomata. Fam. Flustridae.) 



Gen. Char.— Cells contiguous, on both sides of the polyzoary.] 



Description.—- Cells oblong", much elongated ; a series of minute incurved 

 denticles along* the inner edge of the margin ; avicularium large, at the base of a 

 cell, mandible pointed, oblique. 



Reference. — Busk, Voy. Ratt, i., 380 ; Cat. Mar. Pol. Brit. Mus., 49, t. lvi., 

 fig. 7, t. lvii., and t. 1., figs. 3 and 4. 



Queenscliff and other places. 



A very variable species, the only constant character being the 

 minute denticles within the inner edge of the margin of the cells. 

 These can always be detected in some of the younger cells towards 

 the end or sides of the branches. Usually, in addition to the 

 denticles, there is a series of thick, hollow, pointed or blunt pro- 

 cesses projecting from the front of the cell margins. These vary 

 much in number, sometimes being only one on each side of the 

 mouth, sometimes two, and frequently a series extending along 

 the whole length of the cell. They are occasionally dentate or 

 bifurcate. The branches of the polyzoary are generally elongated, 

 strap-shaped, dichotomously branched, truncated at the ends. In 

 other specimens they are much broader, more irregularly branched, 

 and rounded at the ends. In a few, the calcareous matter is very 

 deficient, and the frond is so membranous as to present much the 

 color and appearance of a Carbasea. 



Explanation of Figures. 



Plate 45. — Fig. 1, ordinary specimen, natural size. Fig. la, broader form, natural size. 

 Fig. 16, membranous form, natural size. Fig. lc, portion of fig. 1, magnified, showing two blunt 

 processes on each side of the mouth. Fig. \f, portion of fig. 1 a, magnified, showing a series of 

 large pointed processes along the margins of the cells. Fig. le, cell from near the end of the 

 same specimen, to show the minute sub-marginal denticles. Fig. la", portion of fig. 16. Fig. la, 

 cell towards edge of same, showing the sub-marginal denticles. 



* In different descriptions " zoarium " is used for " polyzoary," " zocecium " is used for " cell," and " ooecium " is used 



instead of " ovicell." 



[27] 





