G. CRISTA. 61 



rampant: opening of the cells garnished with two 

 hairs of unequal length. 

 European seas. 



MAILED. 



7. Crisia loriculata. 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 Jiustro'ides. 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. 



H. 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. 



