152 SPOLIA ZEYLANICA. 



Crustacea and Fish in the Sewage Tanks at Madampitiya. 



Dr. Pearson also submitted a note on the presence of aquatic animals 

 in the tanks of the treatment works at Madampitiya. Healthy fish 

 were fovm.d in the septic tanks where the sewage material was \mder- 

 going treatment. It was not possible for the fish to have entered 

 with the sewage matter, since the latter had to pass through a series 

 of clashing blades which made it impossible for any large body to pass 

 through intact. The only explanation appeared to be that fish eggs 

 were able to pass through and that certain species found the conditions 

 of the septic tanks favourable. Crustacea belonging to the genera 

 Palcemon and Caridina were found in the effluent tanks after the 

 sewage water had been passed through finely divided sprinlders and 

 had flowed through the filter beds. The river is about 100 feet below 

 where the Crustacea were fovmd, and as the ascent is extremely steep 

 it does not ajDpear likely that the shrimps made their way up from 

 the river. 



The Chairman proposed a vote of thanks to Mr. Green and 

 Dr. Pearson. 



Mr. V. A. Juxius proposed, and Dr. Andreas Nell seconded, a vote 

 of thanks to the Chairman. 



