Zoology.'] NATURAL HISTORY OF VICTORIA. {Polyzoa. 



or minutely tubercular, divided by numerous raised lines into irregular spaces, in 

 each of which is usually situated a long narrow avicularium similar to those on the 

 front of the cells. 



Reference. — Hincks, Ann. and Mag*. Nat. Hist., May 1878. 



Port Phillip Heads, 12-15 fathoms. 



The best specimens I have of this species are of small size, one 

 measuring 1 by f inch, and another £ by f. The fenestrse are 

 large, much elongated, usually rather narrower than the interspaces. 

 The cells are oval or irregularly rhomboidal ; they are separated 

 by narrow raised lines which unite with the slightly thickened 

 lateral margins of the mouth at about the middle, forming a con- 

 spicuous angle on each side. The mouth is higher than wide, the 

 lower lip hollowed, slightly thickened, entire, or with a small 

 rounded sinus. Immediately above the junction of the separating 

 lines of the cells the mouth recedes, and the angle here formed 

 frequently gives rise to a jointed spine. In young, growing cells 

 the mouth is nearly round, with a fringe-like upper edge to which 

 are articulated several long, slender spines. A similar border and 

 spines are also frequently present in the marginal cells of older 

 parts. On the front of the cell is an avicularium, frequently situated 

 on an eminence, with a long pointed mandible directed transversely, 

 obliquely, or vertically downwards. The ovicell is rounded, deeply 

 notched below. This notch, however, is probably ultimately filled 

 in. The back of the polyzoary is mapped out into irregular areas 

 by narrow raised vibices, in each of which is one or occasionally two 

 avicularia similar to those found on the front of the cells. The 

 operculum is very peculiar. It is of small size, rounded above ; 

 there is an inner mark, parallel to the free margin except that at 

 about the middle on each side it is sharply inflected inwards ; 

 down the centre is a wide groove, on each side of which, especially 

 towards the base, the surface bulges forwards. 



Explanation of Figures. 



Plate 99. — Figs. 4 and 5, specimens, natural size. Fig. 6, group of cells, magnified. 

 Fig. 6a, dorsal surface, showing the small areas, with narrow avicularia. Fig. 7, young cells, 

 magnified. Fig. 8, small group, showing an ovicell. 



[30] 



