42 Scientific Proceedings, Royal Dublin Society. 
Synchieta tremula, Ehrenberg. 
[The Rotifera, vol. i. p. 128, Pl. XIII. fig. 2.] 
Not common. A few examples only occurred. 
Habitat.—A marsh drain, Co. Wexford; a stream, Co. Waterford. 
Hydatina senta, Ehrenberg. 
[The Rotifera, vol. i. p. 9; vol. ii. Pl. XIV. fig. 1.] 
Crowds of splendid examples of this interesting species occurred 
in a small duck-pond, in the month of July, in company with 
Notops hyptopus, many of which (the Hydatina) were affected by 
the fungoid disease alluded to by Dr. Hudson. ‘The internal 
parasite also noticed by him seemed quite of common occurrence ; 
in one specimen, which had been recently killed on the slide by 
the rays of the sun, there were no less than three of these curious 
pear-shaped creatures tumbling madly over each other in their 
desperate efforts to escape from the body of their dead host; they 
finally effected their escape by making their exit through the 
mouth. I searched the same pond again in the month of Septem- 
ber, and there was not one Hydatina to be found: they had en- 
. tirely disappeared. 
Habitat.—A duck-pond, Co. Waterford. 
Notops hyptopus (Ehrenberg). 
[The Rotifera, vol. ii. p. 18, Pl. XV. fig. 2.] 
As before stated this species occurred in swarms in a duck-pond 
in company with Hydatina senta. The wobbling gait, the curved — 
edges down the dorsal surface, and the truncate corona bulging 
forward toward the centre, afford satisfactory points for identifi- 
cation: It also occurred in other localities, but only as isolated 
specimens. In all cases there were two distinctly separate red 
eyes (cervical), placed, however, so close together as to appear like 
one. Their ultimate union would not be improbable. 
Habitat.—Ponds, bogs, and streams, Cos. Waterford, Wexford, 
and Kerry. 
