— 190 — 



The broad specimens occur at low-water mark or below it, and are thus 

 either left dry for a very short time, or not left dry. 



f. evanescens (C. Ag.). 



F. evanescens G. Ag. Sp. p. 92 et auct. partim. 



The specimens I have referred to this form are all broad, without 

 bladders, and have sometimes an indistinct midrib above. They are 

 rather thick and differ essentially from the main form by the compara- 

 tively broad receptacles, which are 3 — 5 cm. long and 1,5— 2 cm. broad. 

 They resemble approximately the figure given in Ic. alg. hied. Tab. 15. 

 The receptacles are undivided or divided into two or more divisions, and 

 sometimes the divisions have a triangular shape. I have seen specimens 

 with undivided receptacles that were about as broad as long, but in the 

 same plant we can meet with long, linear, and divided receptacles. This 

 form is closely connected to the broad forms of the main form, and 

 there is no distinct limit to be found between them. 



It is found at low-water mark and below it. 



f. linearis (Huds.) Rosenv. Grl. Havalg. p. 834 ; F. linearis Hudson 

 Flora anglica London 1762, Oed. Fl. Dan. tab. 351. 



The frond of the Icelandic specimens is 6 — 15 cm. long and 1 — 

 3 mm. broad, with thin margin and sometimes with an indistinct midrib 

 above. Bladders are wanting. The receptacles are 0,4—3 cm. long and 

 1— 4 mm. broad, they are usually undivided, but sometimes I have found 

 them divided into two portions. They are often inflated. As I have 

 mentioned above, this form is connected with the main form by many 

 intermediate forms. It is certainly one such intermediate form Strömfeit 

 has met with at Eyrarbakki, about which he says that it both resembled 

 F. evanescens f. angusta Kjellm. (Algv. Murm. p. 27) and F. linearis Oed. 

 Fl. Dan. Tab. 351. 



This form grows exclusively in tidepools in the litoral region and is 

 consequently never left dry, except the receptacles, which sometimes rise 

 above the surface of the water. 



f. exposita new name. F. distichus Lyngb. Hydr. Dan. p. 6 exclus, 

 syn. Fucus distichus a, robustior J. Ag. Spetsb. Alg. p. 37 ! ), Kjellm. Arct. 

 Alg. p. 210; F. inflatus f. disticha Borgesen Fær. Alg. p. 465. 



The name F. distichus, I think, ought not to be used of this form, as 

 Linné's description of Fucus distichus: „F. fronde plana dichotoma integer- 

 rinla lineari " , seems to agree much better with other forms of F. inflatus 

 e. g. f. linearis. As it is, at present, impossible to say with what form of 



J ) Judging from Turner's fig. (Hist. Fuc. tab. 4) I think F. distichus f. tenuior 

 J. Ag. is to be referred to f. linearis. 



