42 



Hydatina senta. That he was able to show any mounted speci- 

 mens at all was due to Mr. C. F. Rousselet. Those brought 

 home were not very efiBciently mounted, and Mr. Kousselet 

 remounted them. Generally speaking, the rotifers are not very 

 peculiar, perhaps the most notable being Philodina alata, which 

 has large lateral processes. Referring to P. gregaria, Mr. Murray 

 said that in the localities examined this species was remarkable 

 for the extreme abundance in which it was found this abundance 

 being due to its rapid multiplication, as many as six living young 

 being produced at a birth. It forms blood-red stains on the 

 pebbles in the lakes, and a bottle containing a tilter-paper stained 

 brilliant red was shown to the meeting. The coloration was due 

 to the presence of myriads of this species of rotifer. It was ob- 

 tained in the following manner: A handful of the vegetation was 

 washed in water and the sediment thus obtained was transferred 

 to a bottle. After a while the rotifers came to the surface of the 

 mud, where they formed a blood-red film. A little later they 

 crept up the sides of the bottle till they reached the surface of 

 the clear water. They there formed a crimson ring, and could be 

 easily removed to a filter-paper by inclining the bottle till part 

 of the ring was clear of the water, and lifting the animals by 

 means of a camel's-hair pencil. The filter-paper was then dried 

 and preserved. Photomicrographs of living narcotised specimens 

 of Philodina gregaria were exhibited, and also of several other 

 Hotifers, Tardigrades, and Infusorians. Two new species were 

 mentioned, both belonging to the genus Philodina, P. antarctica 

 and P. alata. 



Much interest attaches to the mode of life of these organisms. 

 The air temperature in latitude 77 to 78 South hardly ever 

 rises above freezing-point. This does not favour a great growth 

 of moss, nor of the rotifers which live upon it. They find a 

 home in the lakes, which, though frozen for ten months of the 

 year, attain to a temperature of as much as 60 F. in summer. 

 There was shown a specimen of the Antarctic vegetation amongst 

 which the animals are found. It is orange-coloured and in large 

 thin sheets, many of which are superposed to form a stratum of 

 considerable thickness, covering small ponds without interruption 

 from side to side. The underside of the sheet is dull green from 

 the presence of numerous algae, green and blue-green. 



The rotifers do not die when the lakes freeze, but go to sleep 



