636 



SUPPLEMENT 



upper part contracts itself, and the margin 

 then assumes a conical shape, with a convex 

 surface ; there are in general but few branches 

 from the principal stem, and these are short 



and thick. It excites an undulatory motion, 

 but neither hairs, nor rotatory motion, have 

 been discovered. The figure represents the 

 vorticella adhering to the monoculus quadri- 

 cornis. 



Vorticella convallaria. These vorticellae, or 

 bell-animals, as they are termed by Baker, 



are generally found adhering to some sub- 

 stance in the water ; they are represented here 

 as found by Rosel, fixed to a curious cornu 

 ammonis, with points projecting from the back. 

 To the naked eye they appear only as so many 

 little white points, but under the microscope, 

 as little bells, agitating the water to a consi- 

 derable distance. The stems of these have a 

 particular motion, they draw themselves up 

 and shorten all at once, taking the form of a 

 spiral wire or screw ; in a moment after they 

 again extend themselves. Many of them may 

 be seen at times adhering to each other by their 

 tails; the cilia are disposed round the mouth, and 

 require a good defining power to exhibit them 



satisfactorily. On reference to the figure, it 

 will be perceived that some of the animalcules 

 differ in appearance from others : those which 

 are nearly circular are in a state of inactivity; 

 others, assuming an oval form, and beginning 

 to open, are in the act of stretching themselves 

 out to take their prey; and such as have taken 

 the perfect cup-like shape, are fully extended, 

 with their cilia in action, collecting food. One 

 is drawn on a considerably enlarged scale, to 

 exhibit more clearly the styli and cilia. 



VORTICELLA SPECIES. 



1. Vorticella cineta. In the form of a trapezium, of 

 a blackish green colour, and opaque. 2. Vorticella sphte- 

 roida. Globose, uniform, and opaque. 3. Vorticella 

 viridis. Cylindrical, uniform, green, and opaque. 4. 

 Vorticella lunifera. Green, the hinder part luminated, 

 with a point in the middle projecting from the edge. 

 5. Vorticella bursata. Green, the aperture truncated, 

 with a central papillary projection. 6. Vorticella varia. 

 Cylindrical, truncated, opaque, of a blackish colour, 

 the fore part ciliated. 7. Vorticella sputarium. Round 

 and prominent, with an orbicular aperture, and long 

 hairs radiating as from a centre. 8. Vorticella nigra. 

 Black, and top-shaped. 9. Vorticella m ultiformis. Green , 

 opaque, variable, with vesicles scattered about the body. 

 10. Vorticella polymorpJia. Many-shaped, green, 

 opaque. 1 1 . Vorticella cucullus. Long, round, the aper- 

 ture or mouth obliquely truncated. 12. Vorticella 

 utriculata. Green, the belly round and prominent, ca- 

 pable of being lengthened or shortened ; the fore-part 

 truncated, much in the shape of a common water-bottle : 

 the neck is sometimes very long, at others, very short^ 

 and filled with green molecules. 13. Vorticella ocreata, 

 Nearly of a cubical figure, the under part bent in an 

 obtuse angle. 1 4. Vortioella Taiga. Cubical, the lower 

 part divaricated. 15. Vorticella papillaris. Big-bellied, 

 the fore-part truncated, with a papillary tail, and a 

 splendid papillary excrescence on the side. 16. Vorti- 

 cella sacculus. Cylindrical, the aperture broad and flat, 

 the edge turned down. 17. Vorticella cirrata. Big-bel- 

 lied, the aperture sinuated, two tufts of hair on each 

 side of the belly. 18. Vorticella nasida. Cylindrical, 

 with a prominent point in the middle of the cup. 19. 

 Vorticella stellina. Orbicular, with a molecular disc, and 

 ciliated margin. 20. Vorticella d-iscina. Orbicular, the 

 edge ciliated, with a kind of convex handle on the un- 

 der side. 21. Vorticella sci/phina. Bowl-shaped, crys- 

 talline, with an opaque spherule in the middle. 22. 

 Vorticella albina. The fore-part cylindrical, the hinder 

 part tapering and ending nearly in a point. 23. Vorti- 

 cella fritillina. Empty, cylindrical, the apex truncated. 

 24. Vorticella truncatella. Cylindrical, stuffed or 

 filled, the apex truncated, with very short cilia. 2,5. 

 Vortacclla limacina. Cylindrical, truncated with two 

 pair of cilia. 26. Vorticella fraainina. Gregarious, cy- 

 lindrical, obliquely truncated, with two pair of cilia, 

 and a fissure or notch at the upper edge. 27. Vorticella 

 crategaria. Compound, with globous naked florets, 

 two ' tentacula, and a branched stem. 28. Vorticella 

 hamata. Purse-formed, the edge of its aperture or 

 mouth set with rigid points. 29. Vorticella crateriform- 

 is. Approaching to a square figure, with fascicles of 

 cilia even at the hinder part. 30. Vorticella canalicula- 

 ta. Dilated, pellucid, with an incision in the side. 3 1 . 

 Vorticella versatilis. Long, spear-formed, but often 

 changing into a pitcher-like form. 32. Vorticella am- 

 pulla. Contained in a pellucid bottle-shaped bag, the 

 head divided into two lobes. 33. Vorticella follicnlata. 

 Oblong, in a bright cylindrical bag. 34. Voriicdla lar- 

 va. Cylindrical, the aperture crescent-shaped, two 

 small thorny points projecting from the hinder part. 

 35. Vorticella sacculata. Like an inverted cone, the 

 aperture crescent- shaped, lower part of the trunk 

 notched, the tail biphyllous. 36. Vorticella aurita. 

 Cylindrical and big-bellied, the aperture destitute of 

 hairs, both sides of it are furnished with rotatory cilia, 

 tail biphyllous. 37. Vorticella tremula. Conical shape, 



