DR. G. DICKIE ON ST.-HELENA MARINE ALGE. 181 
Family VALONIACER. 
Valonia verticillata, Ktz. ? 
A few specimens only, and those very indifferent: it may be 
new; for the present I prefer to consider it a slender and less 
branched form of the above species. 
Geographical Distribution :—Vera Cruz. 
Family UrvacEzx. 
Ulva latissima, L. 
Mr. Melliss found this to be the most common of all the Algæ. 
Geographical Distribution:— Generally distributed in tempe- 
rate and colder oceans. 
Enteromorpha, sp. 
Mere fragments only, found adhering to Laurencia cruciata, 
the structure evidently the same as that of Enteromorpha per- 
cursa, Hook., but too imperfect for identification. 
Summary.—There is therefore only one representative of the 
olive, thirteen of the red, and four of the green series. 
With the exception of Padina, Laurencia cruciata, and Liagora 
viscida, all are very dwarf *. 
Excluding the Valonia and Enteromorpha, which can scarcely 
at present be taken into account, there is not a single form pe- 
culiar to the island; all are plants more or less widely diffused ; 
and most of them occur on both sides of the equator. 
Mr. Melliss states that the seaweeds are found principally 
along the south coast—that, namely, which is freely exposed to 
the current from the Cape, and partly also to any current in- 
fluenced by the constant south-east trade wind. 
Not having access to any complete list of Cape Alge, I can 
only say at present that about one half of the species are also found 
there; Laurencia cruciata is an Australian form; and, with. the 
exception of Ceylon, Pterocladia also belongs to the same region. 
On the supposition that the species here enumerated give a 
fair idea of the Alge of St. Helena, it is rather notable to find 
so few belonging to an island ten miles long by seven broad. It 
* In an account of the Algæ of the Maiden Rocks, two mere islets of basalt, 
about six miles distant from the nearest coast of Antrim, North of Ireland, I have 
recorded five olive, nineteen red, and seven green species, mostly all very small 
in size, whereas the Antrim coast is specially notable for the great number of 
British species (probably two thirds), and for the dimensions attained by 
many of them. (See Trans. Edinburgh Botanical Society, 1871.) 
