96 HISTORY OF BRITISH ZOOPHYTES. 
tain which were the kinds that sparkled, it was necessary 
to make the selection by candle-light, and then removing 
the light to make the experiment. The first I tried was the 
pretty Valkeria cuscuta, and with it I succeeded in striking 
light. From Sertularia polyzonias and Cellularia reptans 
little light arose. With Laomedea geniculata | was very 
successful: on this and on other occasions, it not only, 
when shaken, became very sparkling, but also emitted a 
strong smell of phosphorus. Membranipora pilosa, var. 
stellulata, which spreads itself on a flat frond in a star-like 
form, became doubly entitled to the name of stedlated, as 
every polype in its little cell lighted up its tiny star, so 
that for a short time the polypidom became a bright con- 
stellation. I tried a specimen of Sertularia pumila, re- 
specting which Stewart, as quoted by Dr. Johnston, says, — 
“Tf a leaf of Fucus serratus, with the Sertularia upon it, 
receive a smart stroke with a stick in the dark, the whole 
coralline is most beautifully illuminated, every denticle 
seeming to be on fire;” but as my specimen had lain too 
long on the shore, it did not shine, the polypes, I suppose, 
being dead in their cells. Lustra membranacea, however, 
was very beautiful. When the seaweed on which, like 
silver-lace, it had spread, was shaken or bent,—as the cells 
