40 
Geo. K. Sutherland. 
pycnidium is produced so near the surface that, when mature, the 
upper portion of the body becomes erumpent (Fig 2, 2) and only 
the shortest of ostioles is present; when more deeply buried, a 
longer papilla-like mouth is necessary. In this case, usually the tip 
alone of the latter protrudes. The pycnidial wall (Fig. 2, 4) consists 
of several layers. To the outside there is an investing ring of 
dark thick-walled cells. This is lined by one or more layers of thin- 
walled hyaline parenchyma from which arise the short simple 
conidiophores. The minute conidia or pycnidiospores, at first 
continuous and elliptical, become slightly constricted and finally 
uniseptate (Fig. 2, 5). Frequently they assume a slight bend. The 
appearance of the septum may take place after the expulsion of 
Fig. 2. Diplodina laminariana. 1, thallus showing pycnidia ; 2, diagram 
showing types of pycnidia in section in thallus ; 3, pycnidium ; 4, pycnidial 
wall with conidiophores ; 5, pycnidiospores. 
the conidium. The dimensions and description of this fungus show 
similarity to those given by Cooke and Massee for Phoma 
Laminaria. As the spores of Diplodina are continuous almost 
until maturity, and may be expelled in this unicellular state, it is 
possible that the two are identical. A distinctly different Phoma 
has been met with on Laminaria fronds, but it is of much more 
restricted distribution. Its spores are smaller—being only about 
half the size—and consequently differ from Phoma Laminaria 
which, as noted above, corresponds more nearly with the unicellular 
state of Diplodina. Unfortunately a type specimen of the origina 
