much overgrown by epi- 
phytes, especially in Ska- 
gerak and Kattegat. The 
older parts of the frond 
may be totally covered by 
Bryozoans of the genus 
Membranipora, and in- 
crusting Algæ as Epili- 
thon membranaceum and 
Melobesia limitata may 
appear in the same way 
in the Kattegat, and 
further a number of 
other Algæ frequently 
occur as epiphytes, such 
as Sphacelaria cirrosa, 
Ceramia, Polysiphonie, 
Brongniartella byssoides, 
germlings of Furcellaria 
fastigiata a. o. At the 
coasts of the North Sea, 
Skagerak and the northern Katlegat the specimens of Chondrus growing in shallow 
water (1—2 metres’, more rarely at 5,5 metres’ depth) are often infested with the 
parasitic Pyrenomycete Didymospheria marina (Rostr.) Linp, Danish Fungi as 
repr. in the herb. of E. Rostrup, 1913, p. 214 (Leptosphæria marina RosTR.), that 
gives to the sporangial sori and cystocarps a black colour and develops perithecia 
and pycnidia there. Another parasitic Fungus of the class Phycomycetes, Pleotra- 
chelus pollagaster HENN. PETERSEN (Phycomycètes marins. Oversigt oy. d. K. D. 
Vid. Selsk. Forh. 1905), has repeatedly been found infesting the upper portion of 
fronds of Chondrus crispus growing at various depths in Kattegat and the inner 
waters. 
Fig. 473. 
Chondrus crispus f. ægagropila. Shallow water, Frederikshavn. Photo, nat. size. 
Localities: Ns: Esbjerg harbour on muddy bottom with Zostera vegetation, f. ciliata; Blaa- 
vandshuk washed ashore, various forms, f. equalis, f. ciliata, f. incurvata; Thyborøn, on a groin; Klit- 
møller, within @rhage. — Sk: Hanstholm, Roshage 2 m, mole; Torup Strand, washed ashore (C. M. 
Poulsen) ; ZK? off Lønstrup, 8—9 m; Hirtshals, on the mole and on boulders, down to 2 m depth; 
Skagen, washed ashore on the North beach. — Lf: Common near low-water mark: Lemvig harbour; 
Mulle (J. P. Jacobsen); Thisted; Struer; Nykøbing, harbour and Orodde; Ejerslev Ron; Knudshoved, Fur; 
off Lisehoj North side of Fur; Løgstør; Agersund (Th. Mortensen); Aalborg, large, very broad specimens 
with numerous proliferations (Th. Mort.); Hals (Borgesen). — Kn: Skagen harbour; Krageskov Rev; 
Hirsholmene; reefs and harbour at Frederikshavn; Bangsbostrand; Sæby; several places around Læsø 
Trindel, 8—19 m; several places North of Læsø; Vesterø. — Ke: IO, ZE, ZG, fH, Fladen, 11—17 m; 
Lille Middelgrund, 17—19 m; ES, S.W. of Lille Middelgr., 24.5 m; Store Middelgrund, 10—15 m; Gille- 
leje (Lyngbye); GJ, OO and Vesterlandsgrund north of Gilleleje. — Km: ZC, ZC’ and XB, Kobber- 
