KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 319 
agrees more closely with C. Nordenskiéldianum than with C. gregarium. Fos. after- 
wards found the same plant at Finmarken. He detected there yet another Codiolum, which 
has been described by him under the name of C. longipes and is intermediate between 
C. gregarium and C. Nordenskidildianum. It resembles C. gregarium in size and with regard 
to the proportion in length between the club-head and the stipe, C. Nordenskitldianum 
with regard to the shape of the club-head. After I had’ described C. Nordenskiildia- 
num, | have also myself found a Codiolum on the coast of Finmarken, which I have 
distributed under this name in the above-quoted collection of exsiccatw. It does not 
however completely coincide with the Spitzbergen form, being larger than this and not 
always exhibiting the same proportion as this between the length of the club-head 
and the shaft. Probably it is to be considered an intermediate form between C. Nor- 
denskiéldianum from Spitzbergen and C. lonyipes from the north coast of Nor- 
way. A fourth form of the genus has been lately observed on the north-east coast 
of North America. According to what Fosrm has communicated to me by letter, it 
may be identified with C. longipes, although it differs somewhat from this. It appears 
to me to agree more nearly than C. longipes with C. gregarium. It results from 
these facts that the genus Codiolum has shown itself of late to possess in the northern 
seas a considerable number of forms that are only slightly differentiated and should 
possibly be justly regarded as forms of one and the same species. It is evidently a 
genus in course of developing species. Nevertheless the species distinguished ought 
to be kept up, until more forms shall have been discovered at other places. This will 
no doubt happen now, since more attention has been directed to these small and easily 
overlooked alegw. The last finds prove that they are no rarities and have an extensive 
range on the coasts of the old as well as the new world. In the present work I un- 
derstand C. Nordenskidldianum as including both the form from Spitzbergen and that 
from Finmarken. Its length does not in general exceed 600 u. The thickness of the 
club-head usually amounts to 25—50 w., sometimes 70 «“. in specimens from Finmar- 
ken. The head of the club is in most cases longer than the shaft, sometimes as long 
as or somewhat shorter than the shaft, and elongated-obovate in shape. 
Habitat. It forms a thin cover on stones within the litoral zone on exposed 
coasts, together with Uvrospora penicilliformis. It is gregarious, occurring in considerable 
masses. I have found specimens with zoospores in July on the north coast of Spitz- 
bergen, towards the end of August on the coast of Finmarken. 
Geogr. Distrib. Known from the Norwegian Polar Sea and the eastern Green- 
land Sea. Its northernmost point is Duyinpoint on the north coast of Spitzbergen 
huats.(N 7195 30' 
Localities: The Norwegian Polar Sea: Finmarken at Maasd, local, but abundant. 
The Greenland Sea: the north coast of Spitzbergen, Duympoint, local, not abun- 
1) It has been stated by mistake, that the C. Nordenskidldianum distributed under N:o 425 in Alg. Seand. 
exsice. has been collected at /nsule Spetsbergenses. This is not true. It has been taken on the north 
coast of Norway at Maasé in Finmarken, at the same place and time as the specimens distributed in 
Wittr. et Nordst. Alg. exsice. N:o 51. 
