FAUNA OF A MADRAS POND AND ITS VAEIATIONS. 23 
in this year (1891) it disappeared^ sometime before the 
pond was completely dried up. 
CtELENTEEATA. — I did uot find any representatives of 
this group. Fresh-water sponges although found in some of 
the, Madras tanks do not occur here and Hydra is not; to 
be found. I believe that Hydra has not been recorded from 
Central and Southern India at all. ^ It was recorded by 
Carter from Bombay and is to be found at Naini Tal whence 
Dr. Bourne has had specimens sent to him. 
TuEBELLAEiA. — Rhabdocoela^ Mesostonium sp. ; M icros- 
tomum sp. ; Dendrocoela, Planaria sp. ; 
Mesostomum occurs throughout the year. Microstomum 
suddenly appeared in enormous quantities in March and 
were seen reproducing themselves asexually. 
The dendrocoelous form appeared and disappeared at 
about the same time as {Microstomum) but I never found 
it in great quantity. 
Nbmatoda. — Various free-living Nematodes were to be 
found at all times. 
Oligochceta. — AiJlofioma ; Nais ; Pristina ; Dero. 
I observed 3 distinct species of Dero. In February and 
March all these oligochoeta were reproducing themselves 
asexually. They were most numerous in March and then 
rather suddenly disappeared^ by the end of April very few 
specimens were to be found, and this state of things con- 
tinued until August when they rapidly increased in number 
and abounded during September, October and November. 
They were not so numerous in December and January. 
The rapid increase in the spring is due doubtless to the 
asexual reproduction but I could not find any evidence of 
sexual reproduction taking place either then or at any 
^ I am informed by Dr. Bourne that he has since this was written 
found Hydra in a tank in Triplicane. 
