[ rr ]

PLATE XL.

F I G. I.

VORTICELL A POLYMORPHA.

GENERIC CHARACTER.

A Worm, capable of contracting or extending itself, naked, withrotatory cilia.

Many-shaped Vorticella green, opaque.

It is impossible to describe the various forms those little Insects canassume; and, from the microscope, it is both doubtful and difficult togive a correct figure of it, as the activity of its motions and changesfrequently misplace it from the verge of the focus. It is scarcely per-ceptible to the naked eye, and is generally of a green colour.

F I G. II.

VORTICELLA ROTATORIA.

SPECIFIC CHARACTER.

Cylindrical Vorticella, with a little foot projecting from the neck;a long tail, furnished with four points.

Of all the species of minute Insects, this Vorticelja seems to haveEngaged the attention of the curious most. Baker has described

C 2 it