APPENDIX. 35? 



Halj. — Swan Island, Banks Strait. 



A very beautiful species, the branches resembling strings 

 of minute pearls. The pearly lustre (in the dry state) 

 owing without doubt to the minute sulci on the backs of 

 the cells. These sulci are not, however, consequent upon the 

 drying, because they are equally apparent and constant 

 when the specimen has been immersed in fluid. The 

 species may almost at once be distinguished by the notch 

 in the lower margin of the mouth, which notch repre- 

 sents the central suboval opening present in some other 

 species. 



4. C. ventricosa, n. sp. Tab. i. fig. 1. 

 Cells oval, compressed, rather wide below ; avicularia 

 wide, supporting sometimes a cup-like cavity, sometimes a 

 closed broad conical spine. The prehensile part of the 

 avicularium itself small, seated in a deep notch below the 

 acuminate summit ; lateral area large and well defined. 

 Penestrse 'J, with fissures radiating to a rounded central 

 opening. Anterior surface of cell studded with minute 

 acuminate papUlse ; posterior surface smooth, sometimes 

 spotted. 



Hab. — Bass Strait, 45 fathoms. 



Colour dirty white or brown. Habit stiff, stem 

 strong, straight, branches short and crowded — probably 

 attains a height of four or five inches. The only 

 other species with which it can be confounded is C. 

 amphora, from which it differs in the greater size and 

 more irregular form of the lateral processes, in the pre- 

 sence of the minute papillte on the surface, and in the 

 absence of the narrow longitudinal band on the back ; 

 instead of which the older cells in C. ventricosa exhibit a 

 sort of broad scutum, almost covering the back of the 

 cell and sending off two lateral bands on the sides of the 

 cell, one passing below the avicvilarium and above the 

 lateral area, and the other towards the acuminated apex of 

 the avicularium. It also wants the raised bands wlxich in C, 



Digitized by Microsoft® 



