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One of the Invertebrata. Age of invertebrates. See Age, and Silurian.

Having no backbone; invertebrate.

A limb, or locomotive or prehensile organ, of an invertebrate animal.

animals, as the turtles. (c) The long projecting sucking mouth of some insects, and other invertebrates, as in the Hemiptera. (d) The upper or projecting part of the shell, near the hinge of a bivalve. (e) The prolongation of certain univalve shells containing the canal.

The anterior or cephalic ganglion in insects and other invertebrates.

forming the harder part of the outer integument of insects, crustacea, and various other invertebrates; entomolin.

One of the corneas of a compound eye in the invertebrates. Carpenter.

ally, they are oval, and sometimes more or less spherical in form. In Amphioxus, and most invertebrates, the blood corpuscles are all white or colorless. -- White blood corpuscles (Physiol.), rounded, slightly flattened, nucleated cells, mainly protoplasmic in composition, and possessed of contractile power. In man, t…

include the old red sandstone of Great Britain. They contain, besides plants and numerous invertebrates, the bony portions of many large and remarkable fishes of extinct groups. See the Diagram under Geology.

The lower side of the body of some invertebrates, especially when used for locomotion, when it is often called a creeping disk.

A group of wormlike invertebrates having, along the sides of the body, branchial openings for the branchial sacs, which are formed by diverticula of the alimentary canal. Balanoglossus is the only known genus. See Illustration in Appendix.

One of the artificial group of invertebrates of various kinds, which live parasitically upon the exterior of other animals; an ectozoön. Among them are the lice, ticks, many acari, the lerneans, or fish lice, and other crustaceans.

armor of armadillos and many reptiles, and the shells or hardened integument of numerous invertebrates; external skeleton; dermoskeleton.

vable ball or globe in the orbit, but the term often includes the adjacent parts. In most invertebrates the years are immovable ocelli, or compound eyes made up of numerous ocelli. See Ocellus. Description of illustration: a b Conjunctiva; c Cornea; d Sclerotic; e Choroid; f Cillary Muscle; g Cillary Process; h Iris; i…

A simple visual organ found in many invertebrates, consisting of pigment cells covering a sensory nerve termination.

A thick muscular stomach found in many invertebrate animals.

One the above-mentioned filaments, consisting, in invertebrate animals, of a long, tubular part which is free and flexible, and a bulbous root imbedded in the skin. Then read he me how Sampson lost his hairs. Chaucer. And draweth new delights with hoary hairs. Spenser.

distinct individuals. In the animal kingdom true hermaphrodites are found only among the invertebrates. See Illust. in Appendix, under Helminths.

Having the ganglia of the nervous system unsymmetrically arranged; -- said of certain invertebrate animals.

Having the ganglia of the nervous system symmetrically arranged, as in certain invertebrates; -- opposed to heterogangliate.