32 Lang —Prothalli of Ophioglossum pendulum 
Heneratgoda, and here also the fronds appear among the 
grasses covering the soil. In other localities isolated plants 
were found close to streams growing in the mud. At 
Hanwella the plant grows commonly in the dry compounds, 
but is also abundant in a small Teak plantation and in 
Bar raw a Reserve Forest. In both these situations the soil 
is covered with dead leaves and the undergrowth is scanty. 
The reserved forest of Barrawa is situated on the Puselli Oya, 
a branch of the Kelani river, and is about eighteen miles 
from Colombo. It stands about forty feet above sea-level 
and is very frequently flooded. These floods depend on the 
abundance of the rainfall round the head waters of the 
Kelani river which drains one of the wettest districts in 
Ceylon, and not directly on the rainfall of Barrawa. The 
flood covers the land with water to a depth of fifteen to 
twenty feet, and, as the outflow is not swift, lasts for several 
days at a time. In October, 1900, when this locality was first 
visited, the forest was in flood and no Helminthostachys was 
found. On revisiting the forest in the following March the 
floor of the jungle was dry and was found to be composed 
of fallen leaves mixed with fine-grained mud. In the low- 
lying parts there were very few undergrowth plants, Hel- 
minthostachys being the most abundant. In the spots 
where the mature plants grew, young plants could be 
recognized by the small ternate lamina which appears above 
the surface. These were still attached to the prothallus 
and, by searching in the leaf-mould around, a few free pro- 
thalli were obtained. The following description is based 
on the material thus collected, supplemented by the prothalli 
obtained by Mr. Coomara Swamy, on a subsequent visit to 
the same locality, which he generously put at my disposal. 
The Prothallus. 
The prothalli are subterranean and occur at a depth of 
about two inches. In colour they are brown, the apex and 
younger parts being white. Their position in the soil is 
variable, but most commonly the long axis is vertical, the 
