ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
471 
F, E. Schulze and himself ; it is, of course, impossible to abstract the 
contents of such a key, which, in the present state of confusion, cannot 
but be of value. 
Protozoa. 
Notes on Infusoria.* — Herr E. v. Erlanger gives accounts of a few 
Infusoria. Actinobolus radians Stein is the first dealt with ; when 
swimming it has a pyriform shape, the thicker end being the hinder ; this 
is contrary to Entz’s statement. When at rest the form is often spherical ; 
as the change in form is effected very slowly, the author supposes that 
there is no myoneme present ; this again is contrary to Entz’s view. The 
characteristic tentacles are arranged by twelves in the ciliated grooves, 
where they are separated from one another by regular distances. In 
swimming, the tentacles are retracted, while when the animal is quite 
still they are longer than the axis of the spherical body. When a 
tentacle is highly magnified three parts may be made out in it. The 
proximal part is thick, and conical in form, the next part is longer and 
half as thick, and both are transparent ; the distal third is shorter, highly 
refractive and thinner ; at its end is a capitulum which is much smaller 
than the terminal knob of the tentacles of the Acineta. There is a 
terminal trichocyst which completely distinguishes the tentacle of Actino- 
bolus from that of the Suctoria. Since the discovery of this organism by 
Stein no other observer than Entz has given an account of it. Herr 
Erlanger gives a full account of it. Chlamydodon mnemosyne Stein, which 
the author found at Deauville, is next carefully described ; it, again, has 
been noticed by but few observers. Phascolodon vorticella Stein is little 
known ; it has a very peculiar form, the anterior end being broad and 
rounded, and forming an obtuse angle on the left side ; posteriorly the 
animal becomes gradually smaller and ends in a blunt caudal tip ; on the 
right and left of the ventral surface there is a longitudinally directed 
elevation ; the median part is also convex, though not so high as the ridges. 
There are twelve longitudinal rows of cilia, the arrangement of which is 
fully described, as are other parts of the creature. Hastatella radians g. et 
sp. n. is a free-swimming Vorticellid, characterized by two parallel circlets 
of spines ; these spines are simple outgrowths of the protoplasm of the 
body which are pretty thick at their base, and taper gradually. After 
describing its organization, the author compares the characters of this 
new genus with those of some other Yorticellids ; in some points it 
resembles Gerda and Astylozoon , in others Episfylis umbellaria and Vorti- 
cella microstoma , and in others, possibly, Cyclochseta. 
Structure of Distephanus (Dictyocha) speculum.f — Herr A. Borgert 
comes to the conclusion that the Dictyochidte are independent organisms, 
and that, consequently, their tests are not — as E. Hertwig and Haeckel 
suppose — the isolated skeletal parts of Phoeodaria. Haeckel’s Dictyo- 
chidse are primitively a skeletal species of Phoeodaria. The 
Dictyochidse must be separated from the Eadiolaria, and be placed with 
the Mastigophora. 
The protoplasmic body of Distephanus speculum consists of a small 
rounded soft structure which fills the cavity of the siliceous test, but 
* Zeitschr. f. Wiss. Zool., xlix. (1890) pp. 649-62 (1 pi.). 
t Zool. Anzeig., xiii. (1890) pp. 227-31. 
