128 Australian Polyzoa. 



and lower angle ; lower part of cell-aperture filled in by a 

 calcareous tubercular plate ; a large aviculariuni on the 

 outside of each cell immediately below the aperture. 



Parasitic on other polzyoa and algae. 



Of the genus Emma, lour other species are of common 

 occurrence in Australia. Of these E. tricellata, Busk, and 

 E. (Menipea) Buskii, Wyv. Thomson, are at once dis- 

 tinguished from the present by having three cells in an 

 internode. E. (Menipea) Cyathus, W. Thomson, and E. 

 crystallina, Gray, agree in having only two cells ; in the 

 former, however, the connecting tube is very long and 

 single, while in the latter, in which it is double, there is no 

 opercular spine. 



Family SALICORNARIIDJE. 



Genus SALIC ORN ARIA, Cuvier. 



S. hirsuta. 



Cells in the same series contiguous ; surface granular ; 

 mouth central, lower lip arched upwards, usually with a 

 minute denticle at either side internally ; a long corneous 

 tubular process from the base of the cell. Avicularium 

 replacing a cell, mandible very large, semicircular. 



Common. 



This species forms bushy tufts one to two inches high, of 

 a dirty-white colour. The cylinders frequently present, 

 towards the superior extremity, swollen portions corre- 

 sponding to the situation of the immersed ovicells. The 

 form of the cell varies extremely, being hexagonal, rhom- 

 boidal, with upper and lower edges straight, or the upper 

 arched or pointed ; frequently the upper end is arched, and 

 the lower part much contracted. The forms of cell are pre- 

 cisely similar to those described as occurring in S. farcimi- 

 noides and S. sinuosa. At the base of each cell there is 

 generally a long, hollow, corneous process ; in some speci- 

 mens each cell has two ; and occasionally they are wanting, 

 but never from all the cells of a polyzoary. The ovicell is 

 totally immersed, situated at the swollen part of a cylinder ; 

 the opening is widely lunate, at the summit of an 

 ordinary cell. The avicularium is of great size. It takes 

 the place of a cell in a series ; it is larger than the adjacent 

 cells, of a similar form, granular on the surface ; the man- 

 dible is very large, semicircular, occupies about a third of 

 the cell, and from its situation and form very much resem- 

 bles the moveable lip of an enormous mouth. 



