Search the Dictionary

Min.), native calomel, or bichloride of mercury. -- Horn shell (Zoöl.), any long, sharp, spiral, gastropod shell, of the genus Cerithium, and allied genera. -- Horn silver (Min.), cerargyrite. -- Horn slate, a gray, siliceous stone. -- To haul in one's horns, to withdraw some arrogant pretension. [Colloq.] -- To ra…

ds form, by their rootstalks, a firm, chitinous coating on shells and stones, and esp. on spiral shells occupied by hermit crabs. See Illust. of Athecata.

c sines, hyperbolic cosines, etc. -- Hyperbolic logarithm. See Logarithm. -- Hyperbolic spiral (Math.), a spiral curve, the law of which is, that the distance from the pole to the generating point varies inversely as the angle swept over by the radius vector.

Rolled inward spirally.

he Italian writers of the sixteenth century. Its distinguishing feature is a capital with spiral volutes. See Illust. of Capital. Ionic dialect (Gr. Gram.), a dialect of the Greek language, used in Ionia. The Homeric poems are written in what is designated old Ionic, as distinguished from new Ionic, or Attic, the diale…

A large South African antelope (Strepsiceros kudu). The males have graceful spiral horns, sometimes four feet long. The general color is reddish or grayish brown, with eight or nine white bands on each side, and a pale dorsal stripe. The old males become dark bluish gray, due to the skin showing through the hair. The f…

a vertical fixed ladder, to grasp with the hand in climbing. -- Ladder shell (Zoöl.), a spiral marine shell of the genus Scalaria. See Scalaria.

veral species of the orchidaceous genus Spiranthes, in which the white flowers are set in spirals about a slender axis and remotely resemble braided hair.

A genus of small spiral pteropods, common in the Arctic and Antarctic seas. It contributes to the food of the right whales.

e of descent, especially in the selection of the dam or mother. -- Line conch (Zoöl.), a spiral marine shell (Fasciolaria distans), of Florida and the West Indies. It is marked by narrow, dark, revolving lines. -- Line engraving. (a) Engraving in which the effects are produced by lines of different width and closenes…

A genus of small pectinibranch mollusks, having thick spiral shells, abundant between tides on nearly all rocky seacoasts. They feed on seaweeds. The common periwinkle is a well-known example. See Periwinkle.

A spiral whose polar equation is r2th = a; that is, a curve the square of whose radius vector varies inversely as the angle which the radius vector makes with a given line.

uch that the ordinate of any point will be the logarithm of its abscissa. -- Logarithmic spiral, a spiral curve such that radii drawn from its pole or eye at equal angles with each other are in continual proportion. See Spiral.

A large, pearly, spiral, marine shell (Turbo margaritaceus), from the Pacific Islands. It is used as an ornament.

A genus of spiral gastropod shells, often of large size, characteristic of the lower Silurian rocks.

A large wild goat (Capra megaceros), having huge flattened spiral horns. It inhabits the mountains of Northern India and Cashmere.

Any spiral marine shell of the genus Persona, having a curiously twisted aperture.

te. See Algaroba (b). -- Screw-pod mesquite, a smaller tree (Prosopis pubescens), having spiral pods used as fodder and sometimes as food by the Indians. -- Mesquite grass, a rich native grass in Western Texas (Bouteloua oligostachya, and other species); -- so called from its growing in company with the mesquite tree…

raight filaments, of which the genus Bacillus is a type. 4. Spirobacteria, or bacteria in spiral filaments, as the genus Vibrio.

und living in the tropical Pacific, but many other species are found fossil. The shell is spiral, symmetrical, and chambered, or divided into several cavities by simple curved partitions, which are traversed and connected together by a continuous and nearly central tube or siphuncle. See Tetrabranchiata.…