THUIAEEA. 139 



biserial, adnate to the rachis or " imbedded in the substance 

 of the stem and branches:" vesicles scattered. Polypes hydra- 

 form. — Johnston, 



1. Thuiahia thuia, Bottle-brush Coralline, Sir R. Sib- 

 bald. (Plate YI. fig. 18.) 



Hab. On shells from deep water; Scarborough, Ellis; 

 coast of Durham, J. Hogg; I^orth Durham and Berwick- 

 shire, Dr. Johnston; coast of Cornwall, rare, Mr. Couch; 

 Leith, Jameson; Stonehaven; north of Ireland, Mr. W. 

 Thompson. The name from the Greek word for a cedar. 



Tliis is a very remarkable coralline, and it cannot, in its 

 mature state, be mistaken for anything else. It is from 

 eight to twelve inches in height. The stem is erect, horny, 

 and a little zigzag. The alternate branches below fall off, 

 and leave the stem naked with only a tuft of branches to- 

 wards the top, giving it much the appearance of a bottle- 

 brush. Cells close-pressed to the stem. Vesicles pear- 

 shaped, on the upper side of the branches. Young speci- 

 mens are simply pinnate, without any tuft at top. 



2. Thuiaria articulata, Sea Spleenwort, or Polypody, 

 Mils. (Plate YI. fig. 19.) 



Hab. On shells and stones in deep water, Dublin Bay, 

 EUis ; Donaghadee, Mr. W. Thompson ; Isle of Man, Pro- 



