Additional Notes on Marine Pyrenomycetes. 187 
shown by its presence on much of the material cut, points to the 
association of the two endophytes as being nothing more than 
coincidence. Some sections showed the thallus so riddled with 
these two in addition to Mycosphcerellci that the continued existence 
of the attacked plant seemed nothing short of the marvellous. 
The perithecia are scattered irregularly over the vegetative 
body of the host. While none have been observed so far, on the 
receptacles, it is interesting to note that the number of perithecia 
of the accompanying symbiotic fungus occurring on these is con¬ 
siderably less, owing, it may be, to the presence of the diffused 
parasite Didymospharia inhibiting its fruiting. This point, however, 
requires further investigation. The young perithecium appears in 
the outer cortex as a mass of thin-walled hyphse with dense 
protoplasmic contents, staining deeply; at the same time the 
superincumbent layers become changed and blackened by the 
penetration of hyphae which weave themselves round the cells to 
form a kind of pseudo-clypeus. This commences to show externally 
as a slight blackening whose lighter coloured margins extend 
gradually until a diameter of 175-200/a or even more is attained. 
Each possesses a fringe of irregular, outward radiating arms as in 
Fig. 2, 2, and covers a single globose or flask-shaped perithecium 
whose short ostiole breaks through later. The peridium is nearly 
colourless in the earlier stages and remains so for some time. 
Then the ostiole or tip becomes black, and almost carbonaceous, 
while the outer layer of the basal portion assumes at first a grey 
and finally a distinct dark colour, retaining, however, its membran¬ 
ous texture. Inside are several layers of fine, soft, closely woven 
hyphae, forming a substantial cushion bearing the asci and the simple 
or occasionally slightly branched paraphyses. The former develop 
successively, and, when mature, are more or less cylindrical and 
narrow, or pointed and broad with the ascospores biseriate (Fig. 
2, 4 a). The ascospores are elongate, fusiform, uni-septate, with a 
slight constriction and the ends frequently tapered by the pressure 
of the narrow containing walls. They become faintly coloured at 
maturity. 
With regard to the relationships of this fungus there seems 
little doubt. The entire habit and structure shows a clear similarity 
to several of the species included in Lindau’s second sub-division 
of Didyuiosphceria corresponding to Microthelia Korb., in which 
members of that lichen genus have been included, even when the 
colour of their spores would tend to ally them with Didymellci 
