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Plate xvii.

V ORTICELLA URCEOLARIS.GENERIC CHARACTER.

.T' foall animal, with a vascular cup; the mouth is a t one ende< b and capable of being contracted; the stem fixed.

SPECIFIC CHARACTER.

Single, with a short tail, and toothed mouth.

Th*

^ stIS Animalcum is but perceptible to the naked eye, appearing as^ ' a ‘ w hite speck; the microscope discovers the external covering tofcctl tran *P arent > that all the motions of the animal within are per-j t ^ distinct. It hath a double rotatory instrument, which, however,head^ C ° ncea ^ or ^ ew at pleasure; and it hath power to protrude the^ tail as at Fig . i. or to contract them within the external coat, ta t° V -ing, as at Fig. 2. —When the animal intends to display itsqjt ^ r y instrument, it forces its tail through the hole at the extremity

outer coat, and affixes it to whatever substance is near; but•''hen it r • • •

‘Wirns, it moves its tail backwards and forwards to alfist it.

I'll

e y are found in river, or stagnant, water.

G

F I G.