Ecology.-) natural history of Victoria. [Potion. 



Williamstown, Mr. Maplestone ; Warrnambool, Mr. Watts. 



The aspect and general arrangement of the cells are the same in 

 this species as in the last. There are two cells in each internode, 

 and three in those from which the branches originate. The cells 

 are shorter, wider superiorly, and the free part is not so long j 

 the ovicell is smaller, more elongated, and situated in the angle 

 between the branches ; and each cell, in the typical form, has two 

 long, jointed, articulated spines. One or both spines are frequently 

 broken off, but in that case the mark of the articulation can generally 

 be seen. Occasionally in some or all the cells, in uninjured spe- 

 cimens, there is only one spine. The shorter and wider cell, how- 

 ever, the spine originating nearer the less projecting mouth, and$ 

 when present, the smaller and narrower ovicell, are sufficiently 

 distinctive. The joints also are light-colored. 



I am doubtful to which species Busk's description and figures of 

 C. Edwardsiana refer. The figures have the proportions of the 

 cells of C. biciliata, and may have been taken from an imperfect 

 specimen of the single-spined form. The ovicell, however, is 

 differently shaped* 



Explanation of Figures. 



Plate 39. — Fig. 2, natural size. Fig. 2a, front of branchlet, magnified. Fig. 26, back* 

 magnified. Fig. 2c, ovicell, magnified. 



Plate 39, Fig. 3. 

 CRISIA ACROPORA (Busk) 



Description. — Cells 9-13 in an internode, closely adnate throughout, surface 

 minutely punctate; mouth nearly circular, the outer rim prolonged into a short 

 pointed denticle. Ovicell larg-e, pyriform, frequently annulated. Branches usually 

 given off from the second cell, occasionally higher. 



Reference. — Busk, Voy. Ratt. i. 351 5 Cat. Mar. Pol. Brit. Mus. pt. iii. p. 6. 

 pi. v. 3, 4. 



Williamstown and Queens cliff. 



The only Australian species with which this can be confounded 

 is C. margaritacea (Busk), of which I have specimens from Queens- 

 cliff, but found too late for illustration in the present plate. It is 



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