Himantopus.

A pellucid, invisible, and cirrated worm.

The acarus is lively, conical, ventricose, full of black molecules, with a bright and transparent fore part. The lower part of the apex has rows of long hairs on the under part set like rays. Four locks of long crooked hair or feet proceed from the belly, and it is continually moving these and other hairs in various directions.

The ludio is a lively diverting animalcule, smooth, pellucid, full of small points, the fore part clubbed and a little bent, the hinder part narrow; the base obliquely truncated, and terminating in a tail stretched out transversely. The top of the head and middle of the back are furnished with long and vibrating hairs; three moveable and flexible curls hang down from the side of the head at a distance from each other. When the creature is at rest, its tail is curled; but when in motion, it is drawn tight and extended upwards.

The fannie is found, though seldom, in water where the lemma grows. The cilia are longer than the hairs, and are continually vibrating; it has two moveable curls hanging on the side of the head.

The charon is found in sea water, but rarely. It is oval, pellucid, and membranous, with longitudinal furrows and several bent diverging rows of hair below the middle, but none on the hinder part.

XVI. Vorticella.

A naked worm with rotatory cilia, capable of contracting and extending itself.

The lunifera is found in salt water; has the fore part obtuse, the base broad, and hollowed away like a crescent, with a short protuberance in the middle of the concave part: the fore part is ciliated.

The burfata is found in salt water, and is ventricose, crammed with molecules; the fore part truncated, and both sides of it pellucid: there is a prominent papilla in the middle, which when the animalcule is at rest appears notched, the edge of the aperture being ciliated; the hairs are capable of moving in various directions.

The sputarium is found in October, with the lesser lemma, and is one of the most singular of the microscopic animalcules. When viewed sidewise, it is sometimes nearly cylindrical, only tapering a little towards the hinder part, and having a broad pellucid edge. Viewed from the top, it has sometimes a broad face or disk, furnished with radiating hairs, the under part contracted into a globular shape, of a dark green colour, and filled with small grains.

The multiformis is found in salt water, and very much resembles the former.

The nigra is found in August in meadows covered with water. It may be seen with the naked eye, appearing like a black point swimming on the surface. Through the microscope it appears as a small conical body, obtuse and ventricose at one end, and acute at the other. When the extremities are extended, two small white hooks become visible by the affluence of which,