SERTULARIA. 138 



said, by the zigzag stem, the single upright cell in the angle 

 betwixt the stem and the branch, and by there being only 

 two cells, one on each side on that part of the stem which 

 intervenes betwixt every two branches. 



15. Sertulaeiaoperculata, Sea-hair Coralline. (Plate V. 

 fig. 16.) 



Hab. On seaweeds, especially on the stem of Lamlnaria 

 dlgitata. Common on all parts of the coast. And yet, com- 

 mon as it is, I had been several years minister of an Ayr- 

 shire parish with five miles of sea-coast, from Saltcoats to 

 Irvine, before I ever saw either this or any other zoophyte ; 

 or more properly speaking, before I observed one of them, 

 or gave that degree of attention which is necessary to dis- 

 cern their beauty. When S. operculata was shown me by 

 a naturalist whom I met on the shore, I was so much struck 

 with its elegant structure, that I thought it must be some 

 foreign production, and could scarcely believe that so great 

 a curiosity could be found on our own shores. Ashamed of 

 having so long had eyes and no eyes, I began to make a 

 better use of them; and having detected some other zoophytes 

 of equal beauty, I sent them to my kind and excellent friend 

 Dr. Fleming, who gave me their names and encouraged me 

 to prosecute my marine researches. " It consists,' ' as Ellis 



