F. Børgesen: The Species of Sargassum. 11 



Two forms may be re ferred to this species: 



var. typica. Figs. 3 — 5. 



Fucus bacciferus Turner, 1. c, pi. 47. 



To this variety belongs the forms with globular vesicles with no appendages as 



shown in the typical specimen from the Linnean Herbarium. This variety is nicely 



pictured in Turner, Fuci, \. c, 



var. ciliata n. var. Fig. 7. 



Harvey, Phycologia Britannica, PI. 109. 



KtJTziNG, Tabulæ Phycologicæ, vol. XI, pi. 11, fig. II. 



While the typical form as described above has globular vesicles without any pro- 

 longations at their apex, another form is often found in which the vesicles have 

 shorter or longer fdiform appendages at their top (Figs. 6 and 7). Otherwise it seems 

 to agree with the typical form. I do not think that this form can be kept separate 

 from the above mentioned, typical form, with good justice; specimens occur in which 

 some of the vesicles have prolongations, while others have not (comp. Fig. 6 and Harvey, 

 1. c. pi. 109) and in some of these the length of the prolongations is much variable. In 

 this connection I also want to point out that, ås stated above, the vesicles of S. val- 

 gåre may occur with a leaf-like prolongation. I therefore consider it to represent a 

 variety to which I propose the name given above. 



2. S. Hystrix J, Ag. (compare p. 5). 

 var. fluitans nov. var. Fig. 8. ^^■~~- 



This is the second species which I have collected in the Sargasso-Sea. It is larger 

 and coarser than S. natans; the leaves are broader, linear-lanceolate with serrate 

 margins, the single tooth being proportionally broader and shorter than in S. natans. 

 The midrib is distinct, and cryptostomata are commonly found scattered on both sides 

 of the midrib; in some of the leaves they are almost absent. 



The vesicles are very numerous; they are about as large as a common pea; they 

 are spherical with no prolongations and borne on very short stalks, They are placed 

 in the axils of the leaves, solitary as a rule, but sometimes two vesicles are deve- 

 loped. The stem is provided with short spinules. 



I have considered this form as a variety of Sargassum Hystrix as it seems to me 

 to be very much like the figure of J. Agardh in "Species Sargassorum Australiæ", tab. VII, 

 fig. 1. J. Agardh mentions also, that this species is found floating in the Atlantic 

 Sea; he writes (1. c, p. 91): "nunc in Atlantico circumvaga et sæpissime sterihs." 



These are the forms which I have found in the Sargasso-Sea; that other forms may 

 occur there, is very likely, but those described above are nevertheless the most common. 



2* 



