SERTULARIA. 183 
said, by the zigzag stem, the single upright cell im the angle 
betwixt the stem and the branch, and by there bemg only 
two cells, one on each side on that part of the stem which 
intervenes betwixt every two branches. 
15. SERTULARIA OPERCULATA, Sea-hair Coralline. (Plate V. 
fig. 16.) 
Hab. On seaweeds, especially on the stem of Laminaria 
digitata. 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 8. 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 
