ROTIFERA. 591 
referred to by that observer were found moving freely within 
the general cavity of the body. 
Pterodina possesses five pairs of the usual ciliated appendages, 
the presence of which Leydig was not able to determine. 
From his observations on Euchlanis dilatataj seen in different 
positions, Moxon concludes that the tags,^^ or cilium funnels, of 
this and other Rotifera are triangular enlargements, their (inner) 
surfaces covered with numerous short cilia. It is probable that 
the cilia are on two opposed surfaces, not on a single plane, but 
in any case it would appear that the candle-flame-like appear- 
ance,^^ ascribed to one long flickering cilium contained within a 
blind sac, is delusive. Similar appearances are produced by 
other structures, the nature of which is known, as tlie tube valve 
of Floscularia, the ciliated oesophagus of various Rotifers, and 
the vibratile funnels of the Naids. * 
Weissb observed the expulsion of the egg in a mature 
specimen of Floscularia ornata. The germ-vesicle Was still 
present ; but traces of embryonic strilctrires soon showed them- 
selves, and ciliary movements, which gradually increased in 
energy, could be noticed within the egg at one extremity. 
Rupture of the egg occurred at tliis extremity on the fifth day 
after exclusion. The embryo, thus liberated, was about twice 
the length of its egg- covering, but very unlike the parent 
FloscAilaria, It moved slowly about in a worm-like manner, and 
displayed at its anterior end a circlet of cilia. 
Other embryos distinctly exhibited two red eye-spots before 
their escape from the egg, which, in one case, did not take place 
till seven days after the act of deposition. 
The author thinks it probable that in all Rotifera, except Hy- 
datina senta, the development of the ovum is effected with 
comparative slowness. 
