521 
p. 316) found his Finmark specimens »in 10—20 fathoms attached 
to Lithothamnion soriferum and corals«, and the doubt he expresses 
as to the identity of the Finmark and the Fseroese plant on account 
of their different habitats is now cleared away by the discovery of 
my sublittoral plant. He finds further cause for doubt in the fact 
of his plant being 1—1,5 cm. high only, while Lyngbye records 
his to be »circa pollicem altus«, but here again, I may mention 
that some of my specimens were also about 1 cm. high only, while 
others were almost an inch high. With regard then to the sub¬ 
stratum Derbesia marina grows on, this appears to be very dif¬ 
ferent, Lyngbye found it on rocks, Kj ell man on Lithothamnion 
and corals, and I on Balanus and Serpula , and, lastly, I may add 
that at Lerwick on the Shetland Islands 1 I found it at a depth of 
about 6 fathoms, epiphytic upon the stem of Laminaria hyperborea 
where it occurred as a short cushion about 3 A inches high. 
The Faeroese as well as the Shetland plant agreed well with 
Kjellman’s exhaustive description. I shall in what follows point 
out some of their most important characters. In both plants there 
usually occurred one short cell at the base of each branch — most 
frequently in the English specimen — and a similar short cell in 
the stalk at the base of the sporangium. The erect branches were, 
at their thickest, as much as 54 y thick in the plant from the Faeroes, 
and somewhat thinner, about 50 y in the English one. Sporangia 
occurred in both of them, but unfortunately I did not observe any 
which were quite ripe. Those in the Faeroese specimens were about 
160 y long and 75 y broad, while those in the Shetland specimens 
were about 150 y long and 70 y broad. A similar immature spo¬ 
rangium in the specimen gathered by Lyngbye measured 156 y 
in length and 67 y in breadth. The stalks of the sporangia vary 
considerably in length, as mentioned by Kj ell man (1. c. p. 10); 
those which I examined varied in length from 20—60 y. The spo¬ 
rangia, as I said before, were not fully ripe, so, unfortunately I 
cannot record with any certainty how many swarmspores are pro¬ 
duced in each sporangium, but they were, however, sufficiently deve¬ 
loped for me to ascertain that the number would undoubtedly be 
at least 20. 
1 This year on my way to the Faroes I was enabled to pay a short visit to 
the Shetland Islands, as the Marine Department not only kindly allowed me to 
make the voyage to the Faeroes in the cruiser »Beskytteren«, but also permitted 
the latter to touch at the Shetland Islands. 
