KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 208 
Adnot. 1. F. evanescentis f. anguste proxime accedit Fucus miclonensis J. G. AG. Spetsb. Alg. Till. p. 35, 
39 ct Gronl. Lam. et Fuc. p. 28, saltem quoad specimina Spetsbergensia et Groenlandica. 
Adnot. 2. In grege formarum inter f. bursigeram et f. typicam intermediarum J. G. AGAanvuir Fucus cvanescens 
minor receptaculis inflatis ad I’. bursigerum tendens, me judice est adnumerandus. 
Syn. Fucus ceranoides Pati. Reise 3, p. 34. 
» » Post. et Rupr. Ill. Alg. p. I; Cfr. Gor, Algenfl. Weiss. Meer. p. 55. 
» » Scurenk, Ural Reise p. 546. 
» evanescens J. G. AG. Spetsb. Alg. Till. p. 27, 35, 40; Grénl. Alg. p. 110; Cfr. supra. 
» » Gosr T."'c: 
» » KJeLLM. Vinteralgv. p. 64; Spetsb. Thall. 2, p. 3; Algenv. Murm. Meer. p. 26; 
Kariska hafvets Algv. p. 23. 
» » Quercus Paty. Reise 3, p. 34. Cfr. sub Delesseria sinuosa. 
» vesiculosus J. G. AG. Spetsb. Alg. Progr. p. 2; Bidr. p. 11. 
» » Asum. Alg. Hayes, p. 96 (?) Cfr p. 199 sub. F. vesiculoso. 
» » Croaut, Fl. Disc. p. 457; ex parte. 
» » Dickiz, Alg. Sutherl. 1, p. 140; ex parte(?); Alg. Cumberl. p. 236; ex parte 
» » Eaton, List. p. 44. 
» » LinpBL. Bot. Not. p. 157. 
» » Martin, Met. Observ. p. 313. 
» » Post. et Rupr. Il. Alg. p. LI; saltem ex parte. 
» » ScnuBeLer, in Hevuewin Reise p. 317. 
» » ScoresBy, Account 1, p. 132. 
» » SomMeRF. Spitsb. I'l. 233. 
» » ZELLER, Zweite d. Polarf. p. 85. 
» » Cfr. Martens Voyage Spitsb. p. 77, t. F, fig. b. 
Remark on the determination of the forms. Fucus evanescens has of late become ever 
better known, and the algologists who have had an opportunity of studying it have 
adopted J. G. AGArpu’s opinion that it is to be considered an independent species. It 
was formerly confounded with F. vesiculosus, although it is probably less closely allied 
to this species than to F. edentatus. It differs from the former species by its branching, 
the shape of its segments, its colour and consistency, and above all by the different 
structure of its scaphidia. Of /. edentatus I have, on the contrary, seen forms very 
nearly approaching J. evanescens, and, on the other side, forms of F. evanescens much 
resembling F. edentatus in the shape and size of the receptacles. Nevertheless I believe 
the two species can be distinguished by certain differences in the ramification of the 
frond, in consistency and in the nature of the costa. I have set down here the same 
forms that I have before endeavoured to distinguish and to define. They are certainly 
connected by numerous intermediate forms, but they deserve however to be mentioned 
specially, because they show the limits and directions of the variations of the species 
and differ somewhat with regard to biology and geographical distribution. I have 
arranged under them the forms mentioned by J. G. AGAnrpu in his works on the ma- 
rine Flora of the Arctic Sea. I cannot possibly distinguish Fucus miclonensis J. G. AG. 
from Spitzbergen and Greenland, of which I have seen specimens determined by J. G. 
Acarpu, from low-sized Ff. evanescens f. angusta and from intermediate forms between 
this and f. nana. Fanrtow says of f. miclonensis De ta Pyt. »F. miclonensis of Dr La 
