86 CLASS I.— ORDER II. 



lated, and trichotomous ; cells in threes, cylindrical, 

 with a very small opening ; ovaria oval, and axillary. 



BLACK. 



23. Sertularia nigra. Cells nearly opposite, 

 and very small ; ovaria very large, oval and quadran- 

 gular ; branches pinnated and black. 



Indian and American seas ; and coast of Cornwall. 



CEDAR. 



24. Sertularia cedrina. Cells nearly cylindri- 

 cal, tubular, and imbricated, in four rows ; branches 

 quadrangular, and largest at the summit. 



Sea of Kamtschatka. 



PURPLE. 



25. Sertularia purpurea. Branches quadrilate- 

 ral and dichotomous ; cells nearly oval, tubular, and 

 imbricated, in nearly four rows ; ovaria upright and 

 campanulated. 



Sea of Kamtschatka. 



OBSOLETE. 



26. Sertularia obsoleta. Cells oval, nearly 

 heart-shaped, placed five and five in eight rows; 

 branches alternate. 



Frozen sea. 



WILD PINE. 



27. Sertularia pinaster. Cells in six rows; ova- 

 ria much swelled j branches alternate and pinnated. 



Frozen Ocean. 



DODDER. 



28. Sertularia cuscuta. Cells in groups round 



