48 



Tromsø Museums Aarshefter. 14. 1891 



ted, by its «strongly developed basal layer, by the vertical 

 cell-rows being often branched, and, above all, by the diffe- 

 rent shape and position of the tetrasporangia». At Skorpen 

 in Kvænangen (Tromso amt) I collected a Petrocelis growing 

 on rocks at lo w- water mark of neap tides together with Cru- 

 oria pellita J. G. A g. The basal layer is strongly develo- 





ped but the vertical cell-rows are seldom branched. The te- 

 trasporangia were not fully developed when collected in the 

 beginning of September. They differ from those of P. cru- 

 enta thereby that they are generally situated below the midd- 

 le of the filaments, sometimes at or a little below the middle, 

 sometimes even near the base, and they are (not fully deve- 

 loped), seen from the side, elliptical, oblong or rectangular 

 with rounded corners, 9 — 14 \l long and 4 — 7 [x thick. Thus 

 the specimens probably are identical with P. Middendorfft. 



Callithamnion Brodiæi Harv. 



in Hook. Brit. Fl. II, p. 105, sec. J. G. Ag. Spee. Alg. II, p. 57. 



A few specimens of a Callithamnion collected at Kle- 

 ven (Mandal) I previously referred to C. Brodiæi. They cor- 

 respond well in habit with the specimens of this species di- 

 stributed in W y a 1 1, Alg. Danm. No. 184, but with respect 

 to the ramification they do not fully coincide with Agardh's 

 and H a r v e y's description and the figures in Phyc. Brit. 



4 



pl. 129. I therefore sent a spe eim en to Pr of. J. G. Agardh, 

 who has had the kindness to communicated to me, that it 

 is very nearly related to the above quoted species, but it 

 differs by the ramuli being almost corymbose crowded to- 



■ 



wards the tip of the branches. In this respect it comes nearest 

 to C. guttatum J. G. A g., but the latter has a less develo- 

 ped stem. However, J. G. Agardh records in Epicr. p. 

 35 C. guttatum as a variety of G. Brodiæi. My specimens 

 are, therefore, probably to be regarded as a form of the last 



■ 



named species. They are 2—4 cm. high and were provided 





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