402 Records of the Indian Museum. [Vor Svat, 
had disappeared before the thick brown sediment brought down by 
the first heavy rain of the season. That they had completely dis- 
appeared we established as far as was possible both by stirring the 
pool with our nets and by attaching a townet to a large fishing net 
on the end of a very long bamboo, which the village fishermen were 
passing backwards and forwards over the muddy bottom of the 
deep rocky channel with which the pool commences. The townet 
must have been fishing quite close to the bottom, for it several 
times came up filled with thick black mud. The fact of the 
complete disappearance of the medusae has since been further 
established by the Forest Ranger at Medha, who reported a month 
later that nothing more had been seen of them although the river 
became clear about a fortnight after the sediment first appeared. 
From Medha we crossed over the hills into the valley of the 
Koyna. The pools of which this river is composed in April are 
much broader and often much longer than are those of the Yenna. 
As many of them are connected only by the percolation of water 
through gravel barriers, rain near the source of the river does not 
carry sediment very far down; and all the pools near ambi, 
where we first halted, were still quite clear. Only one of them 
contained medusae, again a pool in which they had been found in 
the previous year, but we were told that they were sometimes 
found in others. The pool in which we found them was long and 
wide without rocky banks, differing completely from that in which 
they had been found at Medha so far as could be judged from the 
surface. One evening, when a strong wind had swept the pool 
from end to end for afew hours, the medusae were found in enormous 
numbers in the shallow water at the leeward end, many of them in 
very poor condition. This shoal had entirely disappeared next 
morning. Medusae were often found in quite shallow water at the 
other end (the one we could most easily get to), having come 
there without the assistance of any wind so far as we could see, 
but these too were often in bad condition. The best specimens 
were obtained by watching for them to come up out of deeper 
water,! but even these seemed to us scarcely as healthy as those 
we saw at Medha. Moreover not a single specimen of unusually 
small size could be found even with the help of townets dragged 
both along the bottom and nearer the surface. From this we think 
it follows either that all the medusae were being produced in some 
unknown rocky cavity out in the middle of the pool and that only 
the feebler adults ever wandered far enough to drift ashore, or 
else that the season of the medusae was drawing to a close and 
would not require any catastrophe to end it completely. In either 
case the existence of a hydroid generation seems to us to be 
clearly indicated, since even the dying medusae showed no signs 
| While at Tambi we tried to ascertain whether they were more abundant at 
certain times of day than at others. Local testimony on this point was conflict- 
ing. We found medusae plentiful between daybreak and sunrise, as well as 
throughout the heat of the day, We seemed to see them best during brief times 
of sunshine, but this may have been due to the illumination of the water to a 
greater depth than when the sun was obscured by clouds. 
