G. CRISIA. 
61 
rampant : opening of the cells garnished with two 
hairs of unequal length. 
European seas. 
MAILED. 
7. Crisia lorkulata. Very branching and dicho- 
tomous. Cells opposite ; opening obliquely trun- 
cated. 
Seas of Europe. 
BIRD’S HEAD. 
8. Crisia avicularia. Stem upright and dichoto- 
mous ; ciliated at the border of the cells, with a ve- 
sicle in the form of a bird's head. 
European seas. 
FLUSTRAL. 
9. Crisia Jiustroides. Frondescent, flat, and dicho- 
tomous ; summit truncated ; cells long, with two small 
teeth on the inner border. 
On the Millepora, otherwise Flustra foliacea, on 
the coasts of Calvados. 
TERNARY. 
10. Crisia ternaia . Branching, dichotomous, ar- 
ticulated, and rampant ; articulations angular, almost 
turban-shaped ; cells in threes, unilateral. 
Scotland. 
THREE-CELLED. 
11. Crisia tricyttara. Frondescent, dichotomous, 
and articulated ; cells oblong oval, larger above than 
below, usually placed two on the same line, some- 
times three : colour greyish yellow ; height about 
five centimetres.— Plate 3. fig. 1. a. B. C. 
On the fucus of Australasia. 
