36 Scientific Proceedings, Royal Dublin Society. 
colour. I have met with many examples answering to the descrip- 
tions of each of the authorities quoted in the Monograph. In the 
long-spined variety (Plate rx. fig. 5) the number varies from 
two to three in the first row, but the two central spines in the 
succeeding row are always highly developed. I have seen them 
moved independently up and down, as though under the control 
of special muscles. Also in one instance I noticed that the upright 
lateral spines were not visible, but whilst I watched, the creature 
suddenly assumed a sitting posture, and the spines, which had lain 
flat against the sides of the body, were flung upward with a jerk, 
and after some time were withdrawn entirely into the integument, 
and I found one example with no spines at all. 
With regard to the short-spined variety, Dujardin’s description 
“tout herissé d’épines”’ is most appropriate. At the juncture of 
every segment there is a closely set row of short, pointed, upright 
spines, which continue round toward the ventral surface. These 
cause the body, in many instances, to be so overlaid with sediment 
that it is difficult to discern them. There is a considerable diffe- 
rence between these two varieties. In the latter, or short-spined 
variety, the body is deeply corrugated longitudinally, and though 
there is a notable swelling in the central segment, the succeeding 
portion does not terminate abruptly towards the base of the foot 
as in the former, but descends gradually; the toes are also very 
small. The colour is sometimes white, but generally shades from 
light amber to brown. Its manners are slow and timid, as it crawls 
into the axils of moss leaves, and persistently hides itself therein. 
Habitat.—Ponds, bogs, and streams, Cos. Wexford and Water- 
ford. 
Rotifer vulgaris, Schrank. 
[The Rotifera, vol. i. p. 104, Pl. X. fig. 2. ] 
Common everywhere. 
Rotifer macroceros, Gosse. 
[The Rotifera, vol. i. p. 105, Pl. X. fig. 5.] 
Though not common, several fine examples have occurred. 
The unusual length of the antenna, its forward direction and 
