4i 
Marine Fungi hnperfecti. 
Phoma has not been available, and consequently its connection with 
Diplodina and the smaller-spored Phoma could not be determined. 
With reference to the naming of the species under considera¬ 
tion, a distinct disadvantage of the present artificial system, adopted 
with regard to pairs of genera like Phyllosticta and Phoma, or 
Ascochyta and Diplodina, may be noted. A generic distinction, 
based almost entirely on occurrence on the leaves in spots or on 
the stems, while applicable to fungi on higher plants, breaks down 
when it has to be applied to those occurring on Thallophyta. Even 
its application in the former has led to abuse and needless multipli¬ 
cation of species which can only be rectified by careful study of life 
histories and culture work. In the present instance, while the 
distinction laid down by Diedicke in thepycnidial walls of Ascochyta 
and Diplodina has been adopted in order to place this species in 
conformity with the existing classification, neither the generic value 
of this distinction, nor its universal application can be accepted as 
proved. The case for these pairs of genera is anything but 
satisfactory. 
FUSIDIUM MARITIMUM nov. sp. (Fig. 3, 1-2). 
Mycelium hyaline, creeping, diffused ; conidiophores erect, 
simple or slightly branched with very long chains of conidia; 
conidia hyaline, fusiform or cylindrical with pointed ends, 12-20/x 
X 3-5/a. 
Hab. Saprophytic on Laminaria fronds and Pelvetia thalli. 
Orkney and Dorset, 
This species of Fusidium occurs both on fronds collected above 
high tide mark and on decaying thalli periodically submerged. 
Freshly collected fronds from the tidal zone, isolated and grown in 
moist stoppered vessels in the laboratory, soon develop the hoary 
fructifications of this species. Its mycelium may penetrate the 
substratum or form loose webs over the surface layers. It is 
regular and hyaline, bearing numerous erect, simple or rarely 
branched, short, tapering conidiophores which merge into the long 
chains of conidia. These consist frequently of hundreds of units 
and reach a length of several millimetres. While the shorter 
chains are borne aloft, the longer ones are stretched and supported 
either on the conidiophores of Cladosporium, when present, 
or on the erect portions of one another. They form an irregular 
silvery lace work over the surface. The conidia are hyaline, 
fusiform or pointed cylindrical bodies. The points of contact are 
slightly flattened as in Fig. 3, 2. 
