168 MR. А. D. COTTON ON CRYPTOGAMS 
according to our observations, Macrocystis does not nearly approach these 
dimensions. The largest stranded specimen I have seen was one thrown on 
the shore of Port North beach after a heavy gale. The basket-like root 
measured exactly 36 inches in diameter, and the total length of the plant 
when stretched out along the shore was 195 feet. On one occasion while 
steaming up Falkland Sound I had exceptional opportunities, owing to the 
calmness of the sea, of making some fairly accurate observations as to the 
approximate lengths of floating specimens. We were steaming near Swan 
Island, where the water was never less than 16 fms. in depth, and the long 
trailing stems and fronds of this seaweed floated on the calm surface of the 
sea. Besides being a complete calm, it was slack water, so that the obser- 
vations were made with a tolerable degree of accuracy. Taking the length 
of the steamer as 70 feet, and the depth of the water as 16 fathoms, the 
captain and I arrived at the independent conclusion that these examples of 
Macrocystis measured between 150 and 170 feet in length.” 
Skottsberg devotes 59 pages to Macrocystis, and his account is practically 
a memoir on the morpholgy and anatomy of the genus, though notes on the 
biology, phylogeny, and a review of the varieties and forms that have been 
described, are included. 
In the work on Peru alge just published by Howe (^14) it will be seen 
that he is inclined to believe that “two reasonably distinct species" of 
Macrocystis occur on the west coast of South America (рр. 60-66). 
CÆPIDIUM ANTARCTICUM, J. Ag. т Hohenacker, Alg. exsice. по. 320; Till 
Alg. Syst. iv. p. 60. 
E. Falklands ; Port Stanley, Zohenacker; Port Louis, upper sublittoral 
and littoral rocks and pools, Skottsberg. 
Distris. Falkland Islands, S. Georgia. 
This curious alga, described from rather scanty material by J. Agardh, 
remained little known till rediscovered by Skottsberg. The latter gives 
descriptions of its early stages, and then proceeds to point out a most remark- 
able dimorphism, namely the possession of Colpomenia-like shoots. Agardh 
noted that it had a prostrate thallus and described rather vaguely the 
upright fertile shoots, and Skottsberg believes that the bladder-like structures 
found on it are also part of the plant itself. 
Having regard to the wealth of preserved material studied by Skottsberg, 
one would be inclined to accept this conclusion in spite of its being so 
unexpected. Dr. Yendo, however, who has examined Agardh’s material, 
assures me that he cannot accept Skottsberg’s interpretation of the genus. 
The type aceording to Yendo is a Chordaria which possesses creeping 
branches and upright shoots. One specimen lacks the upright branches, but 
the other has several, and resembles very much an old and nearly decayed 
plant of Chordaria abietina (cf. Setchell & Gardiner, pl. 18, figs. 16 & 17). 
