— 189 — 



into two or rarely more divisions. This form I think is fully identic 

 with F. inflatus f. latifrons Foslie (Contrib. I, p. 67). By a series of in- 

 termediate forms this form is connected with the narrower forms. An- 

 other remarkable form occurs at half-tide level on exposed coast having 

 6 — 10 cm. long, linear receptacles; the frond is thick and the divisions 

 comparatively narrow. This form must be regarded as identic with the 

 typical F. edentatus De la Pyl. It is connected with the broad form, and on 

 the other hand also with f. linearis and f. exposita. F. evanescens f. an- 

 gusta Kjellm. is to be regarded as transitional form between it and f. li- 

 nearis. Specimens (fig. 24), which 1 think referable to F. inflatus f. reducta 

 Kjellm. (Handbok p. 12, Fig., Arct. Alg. Tab. 19, f. 1-3), are also to be 



Fig. 24. Fucus inflatus L. f. reducta Kjellm. 1 : 2 (cfr. the text). 



placed between it and f. linearis, but nearer to the last-named form. 

 F. evanescens * dendroides Strömf. is one of the transitional forms be- 

 tween the main form and f. exposita, a circumstance also pointed out 

 by Strömfeit. The specimens I have referred to f. dendroides Strömf. 

 agree well enough with Strømfelt' s description, but the receptacles are 

 somewhat longer than figured by him (1. c. Tab. 111). It is to be placed 

 nearer the main form than f. nana Kjellm. and f. contracta Kjellm., which 

 are closer related to f. exposita. 



The main form is exceedingly common at half-tide level and being- 

 very gregarious it forms, in company with Ascophyllum nodosum and 

 Fucus vesiculosus, the Fucus-zone, found elsewhere on rocky coasts, and 

 especially its lower part. It is left dry for about 6 hours at ebb-tide. 



Botanisk Tidsskrift. 25. Bind. 13 



