SOME OBSERVATIONS ON ACINETARIA. 385 
equally unfortunate, since Sand, in his monograph on the 
Acinetaria, says, “ La classification de ce genre est provisoire; 
la mode de nutrition et de reproduction et n’ayant pas été 
observé.”’ 
The resemblance of this animal to the fixed stage of Tachy- 
blaston is very striking, and this resemblance becomes even 
more significant when Robin’s account of the formation of a 
second kind of small bud in Ephelota is taken into con- 
sideration. Robin did not follow the relation between the 
nuclei of these buds and the Ephelota, and Biitschh 
(p. 1894) refused to admit that these structures could really 
be regarded as buds of the Hphelota. From the considera- 
tion of these points, I think it very probable that Robin’s 
“ Acinetopsis rara”’ is merely a stage in the life-history 
of Tachyblaston ephelotensis. After the development 
of the theca the Tachyblaston starts budding very rapidly, 
the number of buds reaching twelve or fourteen. Hach bud 
is provided with a single thick tentacle, the size of which, in 
comparison with other Acinetaria, seems out of all proportion 
to the size of the body. The bud, in this fully-formed condi- 
tion with a contracted tentacle, has rather an elongated pear 
shape, the stalk of the pear being formed by the tentacle. 
In the centre of the body there is a large vacuolated nucleus ; 
at the opposite pole to the tentacle the bud is produced into a 
curious short tuft, which I am inclined to regard as an adhesive 
organ. (This bud seems to bear a curious superficial resem- 
blance to the genus Rhynceta, described by Zenker, from 
the appendages of a fresh-water Cyclops [Pl. VIII, fig. 10]). 
If the living buds are watched carefully it will be found that 
some of them shoot out their tentacles, which, at the same 
time, become very thin, to a length fully equal to that of the 
stalk and theca, about "07 mm. The tentacle then sways to 
and fro in a way that recalls the tentacle of Urnula. If the 
tentacle comes in contact with a foreign body, e. g. the stalk of 
an Ephelota,it retracts, and the bud is pulled out of its theca. 
Very frequently the bud remains for some time attached 
to its tentacle, swaying in a curious pendulum-like manner. 
