138 
PROCEEDINGS OE SOCIETIES. 
The cell walls are very evidently formed of two membranes, which 
remain distinct. 
In dried specimens the inner and stronger coat retains its form, 
while the outer appears to invest it in loose, wrinkled folds, expanding 
into an irregular projecting frill round the mouth. When the coenoe- 
cium is boiled, to expel the air and expand the tissues, the water passes 
freely between the two layers, raising the outer wall into distinct pa¬ 
pillae, and showing it loosely hung round the cell. 
The true avicularian chamber is a continuation of the inner cell- 
wall, hut the hollow lateral processes, whether cups or spines, are 
formed of the thin outer membrane alone. 
7 .—Catenicelljs vittatae {Busk). 
9. — C. formosa (Busk). 
Yan Diemen’s Land; Dr. Harvey. 
10. — C. elegans (Busk). 
Bass’s Strait; parasitical on Algae and on other Polyzoa; abundant; 
Dr. Harvey. 
11.— C. Damom, n. s. Plate XI., Pig. 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. Yittae 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 Premantle district, Western Australia (Har¬ 
vey) ; and the narrower is abundant, of a cinereous gray, on Ballia sent 
from Port Pairy 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 XIII., Pig. 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; vittse linear, lateral, extending nearly the whole length 
of the cell. Ovicell (?). 
Coenoecium 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. 
