60 CLASS I.— ORDER I. 



IVORY. 



1. Crisia eburnea. Upright, articulated and branch- 

 ing; cells alternate, tnmcated, and slightly pro- 

 jecting ; ovaria gibbous. 



European seas. 



CILIATED. 



2. Crisia ciliata. Cells almost lateral, alternate ; 

 the opening large and oblique, garnished with nume- 

 rous hairs unequal in length. 



European seas. 



hairy. 



3. Crisia pilosa. Stem upright and dichotomous, 

 cells oblique ; the opening garnished with one or two 

 long flexible hairs. 



Mediterranean. 



RUGGED. 



4. Crisia scruposa. Rampant and dichotomous ; 

 cells united and alternate : the opening oval, and bare. 



Seas of Europe, Asia, and America. 



THORNY. 



5. Crisia muricata. Stem articulated and dichoto- 

 mous. Cells alternate, and garnished on their upper 

 part with some sharp tubercles ; the opening toothed ; 

 teeth silky. Colour, a dull white ; height about one 

 centimetre. 



On the Fucus Horneri in the seas of Japan. 



rampant. 



6. Crisia reptans. Articulated, dichotomous, and 



