82 DUBLIN UNIVERSITY 



The true avicularian chamber is a continuation of the inner cell- 

 wall, but the hollow lateral processes, whether cups or spines, are 

 formed of the thin outer membrane alone. 



7. — Catenicell^: yittatje (Busk). 

 9. — C./ormo8a (Busk). 

 Van Diemen's Land ; Dr. Harvey. 



10. — C. elegans (Busk). 

 Bass's Strait ; parasitical on Algae and on other Polyzoa ; abundant ; 

 Dr. Harvey. 



11.— C. Dawsoni, n. s. Plate VIII., Fig. 1. 



Cells rounded, gibbous ; lateral processes large, curved forwards and 

 outwards, blunt, with usually a little depression, apparently an abor- 

 tive avicularium at the apex. Cell-mouth rather small, rounded; 

 operculum prominent. Surface of cell irregularly dotted with minute 

 papillae. Vittae broad and short, sublateral near the base of the cell. 

 Ovicell (?). 



This species does not seem to attain a large size. There appear to 

 be two varieties, a broader and a narrower, but agreeing in all essential 

 characters. 



The broad form occurs of a fine yellowish-brown colour, and in great 

 beauty on Algae from the Fremantle district, Western Australia (Har- 

 vey); and the narrower is abundant, of a cinereous gray, on Ballia sent 

 from Port Fairy by James Dawson, Esq., of Kangatong, to whom I am 



indebted for many Australian rarities, and for much curious informa- 

 tion. 



12.— C. castanea, n. s. Plate VI., Fig. 3. 



Cells ovate, elongated. Superior lateral processes small and rounded ; 

 united above the cell aperture by a smooth prominent ridge; the lateral 

 processes continued round the lower angles of the mouth, so as almost to 

 form a corresponding ridge beneath. 



Cell mouth small and round. Operculum very thick. Avicularia 

 small, lateral ; vittae linear, lateral, extending nearly the whole length 

 of the cell. Ovicell (?). 



Ccencecium forming graceful curling tufts. Cells of a rich chestnut 

 hue,*contrasting well with the bright red of the fibrous compound stem. 

 Allied to C. gibbosa (Busk), which does not occur in the collection. 



Bass's Strait; Dr. Harvey. 



