NOTES ON THE FAUNA OE FALMOUTH. 81 



were secured. The presence of this species in this district is of 

 exceptional interest, for I have been on the look-out for it for 

 many years, and this is the only time I have ever met with it in 

 any of my gatherings. P. H. Gosse detected the presence of 

 this rotifer in July, 1850, in some water sent him from the Naze, 

 on the Essex coast. The same gentleman four years later 

 observed numbers of the same species in the sea at Tenby. 

 Lastly, Mr. Hood, of Dundee, captured some specimens in the 

 estuary of the Tay, about twenty years ago. These are all the 

 recorded instances I have been able to discover of this species 

 having been detected in sea-water on the shores of the United 

 Kingdom. 



Perhaps the most striking feature in connection with this 

 species is the fact that it is one of the causes of luminosity of 

 the sea. From as close an examination as possible of the limited 

 material at my disposal, I am inclined to imagine that this 

 phosphorescence is not confined to any one spot, but is scattered 

 throughout the entire animal. 



From the 2nd, when 46''F. was recorded, to the 20th, when 

 50'^F was noted, there was a slow but almost unbroken rise in 

 the surface temperature of the sea. During the remaining ten 

 days of this month the temperature varied but little, 51'6°F 

 being recorded on the 30tli. 



The gelatinous alga, Tetraspora Pouchetii, whose presence in 

 the sea has been recorded during the joast ten years in varying 

 quantity, was first noticed this year on the 27th, and from that 

 day to the 10th of the following month they steadily increased 

 in quantity. Once only, viz., on the 10th May, were these 

 Tetraspores present in sufficient numbers to be easily detected in 

 the sea with the naked eye ; and on no occasion did their 

 presence interfere with the use of the townet. 



May. — The surface temperature of the sea during this 

 month was very uniform. On the 1st 52°F. was noted, and by 

 the 16th the temperature had risen only to 52'6°F. From that 

 day to the close of the month it altered but little, varying from 

 53-9''F on the 23rd to 54°F. on the last day of the month. 



The contents of the various townettings made during this 

 month contained nothing: of interest. 



