ARCHER, ON PALMOGL@A MACROCOCCA. 109 
in Britain, was got by Mr. Barlee in Shetland, in 1858, and 
recognised at the time, but, by some oversight, it has not 
hitherto been announced as British. It is stated by Pro- 
fessor Sars to be not uncommon on some parts of the Nor- 
wegian coast, in about forty fathoms. Professor Busk has 
recorded and figured it among the Polyzoa got by Mr. 
McAndrew on that coast, and in his ‘ Polyzoa of the Crag,’ 
points out its distinctness from H. frondiculata, and proposes 
for it the name of borealis, which I now adopt. It differs 
from H. frondiculate, in being much smaller, less expanded, 
and more robust, in proportion to its size; the surface, too, 
is much less strongly striated; another difference will be 
found in the character of the marginal cells; these in the 
southern species are usually set in diagonal rows, which is 
not the case in H. borealis. But the most decided difference 
is in the ovicells. Those of H. frondiculata are oblong, 
strongly keeled along the top, and striated at the sides, with 
the aperture projecting above into a curved tube (Pl. V, 
fig. 7); but in H. borealis they are globose and reticulated, 
or punctured over the surface, with a tubular aperture at one 
side. The ovicells in this genus are very peculiar. They are 
large, and developed from the general polyzoary at the back 
of a branch, apparently unconnected with the individual 
polypides, thus showing a decided zoophytic character. 
An Envravour to identify Patmoct@a Macrococca (Kiitz.) 
with Description of the Puant believed to be meant, and 
of a New Srerctigs, both, however, referable rather to the 
Grenus Mrostanium (Nag.). By Wiiiiam Arcuer. 
(Read before the Natural History Society of Dublin, January 9, 1863.) 
Berore proceeding to the subject proper of this communi- 
cation I shall call to mind the characters of the genus 
Palmogloea (Kiitz.) itself, thus defined by Kiitzing :*— 
“Stratum gelatinosum difforme indeterminatum, ex cellulis 
sparsis polygonimicis in substantia gelinea nidulantibus, com- 
positum.” Now, such a diagnosis of the genus, while it does 
not seem calculated to exclude all that it ought, appears to 
me to omit an additional important character pervading all 
the species intended to be included therein (if we except, as we 
ought, Palmoglea Roemeriana Kitz.), and that is the elon- 
* *Species Algarum,’ p. 227, 
