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of North Europe. The cystocarps have everywhere been met with only in winter 
(Plymouth December to February, west coast of Sweden December (Kyrın), west 
coast of Holstein December (REINKE), Færûe Islands November (BORGESEN)). The 
tetrasporangia were met with only in February and March at Plymouth (Srurch). 
At the Faröe Islands (BorGESEN), in Kristiania Fjord (GRAN) and at the coast of 
Bohuslän, Sweden (Kyrın) they were met with in April or May, at Helgoland 
(Kuckuck) at the end of May, at the coast of Halland sparingly in June and July (Kyrın), 
and at Gotland in the Baltic Sea at the end of June (Svepezius). The sporangia thus 
generally develop on the North-European coasts in late spring, at Plymouth earlier, 
and in the inner Danish waters partly a little later (June, July, once in October). 
In the Arctic Sea, on the other hand, the biology of the species seems to be very 
different, for in Scoresby Sound (East Greenland) it was found with cystocarps in 
April and July, while tetrasporiferous plants were not met with at all. 
Kyrın (1907 p. 128) has emphasized the fact that the tetrasporiferous specimens 
found in April grew exclusively on branchlets of the host-plant which had devel- 
oped later than December and concludes that they must have arisen from the 
carpospores of the specimens occurring in December. It must really be supposed 
that the species at the coasts of North Europe offers a rare example of a regular 
alternance of a sexual generation in winter and a tetraspore-generation in spring 
(or summer), while in the Arctic Sea one sexual generation only is produced. The 
fact that Harveyella mirabilis has only been observed with tetrasporangia in the 
inner Baltic Sea (Bornholm, Gotland) must perhaps be explained by the lack of 
dredgings during the winter in these waters. 
Localities. Not observed in Ns, Sk and Lf. — Kn: KA, Aalbæk Bugt, 13m (+ 5'); TX, North 
of Hirsholm, 9m ($ 1); TL, West of N. Ronner, 7.5 m (8 9); FE, Læsø Trindel 9—11 m (+ 7). — 
Ke: fH, cast of Fladen light-ship, 17 m (8 10). — Ks: OS”, Hastens Grund, 16 m (+ 4): at Hesselo 
(+5); aU Lumbsaas mill in South 32° West, 13 m. — Sa: KM, east of Oreflippen, 9—17 m (+ 5); 
DK, Bolsaxen, 13—15 m (+ 5) — Lb: OB, at Stavrshoved, 9—11 m (unripe + 3); DF, Remmen east 
of Bogø, 5.5 m (+ 5); DE, by the broom at Thoro Rev, 5.5 m (+ 5); dH, east of Hesteskoen, 15 m 
(+ 6). — Sf: CC, south side of Hornenæs, 7.5 m (8 9); UV, north of Ærø, 13 m (+ 5). — Sb: gy, 
Mollegrund, 8 m; cL, NE of Sprogø, 25—27 m (+ 6); NN, Sprogø light-house i NE ‘/: E 3'/s miles 19 m 
(© 1); AB north of Nyborg, 7.5 m (+ 8); Nyborg (Lyngbye); UE, by the buoy of Vresens Puller, 7 m 
(+5); UF, by Hov Sand, 8.5 m (+ 5); UT, Langelands Belt, 19 m (+5); UJ, near Onsevig, 7.5 m 
(+ 5); DR, by the broom of Albu Triller, 8.5 m (+ 5). — Su: Off Hellebæk (+ 4); near Helsingør 
(Liebman), (QC 12); OJ, Nivaa Flak, 6m (+ 4, one sp. with 2); OG, by Taarbæk Rev, 6m (+4); east of 
Taarbæk Flak 12.5 m (S. Lund, +4 910); Charlottenlund (Hoffmeyer). — Bw: dM, Flensborg Fjord, 
east of the broom at Krage Sand, 14 m (+ 6); dK, Pols Rev south of Als, 6—7 m (+ 6); UL, Femer- 
belt, Øjet, 20 m (+ 5). — Bm: VJ, off Hjelm, Møen, 6 m (+5); VG and QS north of Møen (+ 5 and 
& 7); VD at Bogestremmen, 7.5 m (+ 5). — Bb: Davids Banke, 15 m (4 7), 19—21 m (+ 7); near Salt- 
hammer Rev, 24.5 m (+ 7). 
1 — designates tetrasporangia, d antheridia, ® carpogonia, ©) cystocarps, the number added being 
the number of the month. 
