TRANSLATION. 
CoNCERNING SOME LiTTLE-KNOWN Forms or ANIMAL. 
By Exias Mecznixow.* 
I pusxisH the following remarks because, however deficient 
and incomplete they may be, yet they touch upon a number 
of interesting and almost forgotten animals whose natural 
history is so little known, that every fact that relates to them 
deserves attention. 
I. Comtonotus anv its AtLies.—Ehrenberg has described 
under the name of Chetonotus and Ichthydium two genera, 
which, together with Ptygura and Glenophora, he considered 
as Rotatoria, forming a separate family of themselves. 
Dujardin considers these two genera, together with Coleps 
and Planariola, as representatives of a particular division of 
Infusoria, “ Infusoires symmetriques.” Other naturalists, 
such as Vogt and Perty, have classed the Ichthydina with 
the Vermes. This idea was taken up with great zeal by 
Max Schultze, who added to the two former known genera 
a new one, Turbanella. This able naturalist considering 
the Ichthydina to be animals most nearly related to the Tur- 
bellaria, places them near the Microstoma and Dinophilus, 
as Arhynchia monoiea. Schmarda considers the Ichthydina 
to be Annelids, and places them under the Naids. Leydig 
and many other naturalists hold the opinion of Schultze. 
In recent times one has almost forgotten the Ichthydina, 
because neither Carus nor Troschel mentions them in their 
handbooks. 
Ehlers alone mentions them, but without saying anything 
certain about them ; he says, ‘The Ichthydina are wrongly 
connected with the Rotatoria. I do not know if a muscular 
system lies under their chitinous integument, but I should 
guess from the bristles on Turbanella, and from the organisa- 
tion of the digestive tube in all, that they form a small particular 
division of worms which is best placed under the Nematodes.” 
* Translated from Kolliker and Sicbold’s ‘ Zeitschrift,’ 4th part, 1865. 
