description, belong to C. pannosa, or at least to the Ronndstone
plant so named. I am indebted to my friend Mr. Thwaites,
for suggesting that our plant [C. lamellata, MS.) might be the
C. semiplena of Agardh, and, though I have seen no authentic
specimen, I have little doubt that this is so. At least, the specimen
in my copy of Areschoug’s ‘ Algæ Scandinavicæ,’ which
is quoted by Kützing under his Leibleinia semiplena, seems
identical witlr our Irish specimens here figured, hat is less luxuriant.
The species would appear to have a wide range, both in
the warmer and colder seas of Europe. Specimens from Cherbourg,
communicated by II. Lenormand, doubtfully marked
C.pulvinata'^ Ag., are very similar to those from the opposite
shores of England.
. 1 . C a l o t i i k i x s e m i p l e n a , a mass of laminated tu f t s :— the n a tu ra l size.
2. Tilaments from the sam e:— magnified. 3. Portions of filaments:— more
higlilg magnijied.
‘i '■
