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d in Crustacea, Mollusca, etc., usually called the liver, but different from the liver of vertebrates.

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

Having the vertebral column evidently continued into the upper lobe of the tail, which is usually longer than the lower one, as in sharks.

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

Having the tail nearly or quite symmetrical, the vertebral column terminating near its base; -- opposed to heterocercal.

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

A process, or other element, of a vertebra developed from the ventral side of the centrum, as hæmal spines, and chevron bones. -- Hy`pa*po*phys"i*al, a.

Beneath the axis of the skeleton; subvertebral; hyposkeletal.

A lateral and backward-projecting process on the dorsal side of a vertebra. -- Hy`per*ap`o*phys"i*al, a.

layer which lies beneath the chitinous cuticle of arthropods, annelids, and some other invertebrates.

Under the tongue; -- applied esp., in the higher vertebrates, to the twelfth or last pair of cranial nerves, which are distributed to the base of the tongue. -- n.

A grand division of the Vertebrata, including the Amphibia and Fishes.

Below the vertebral column, subvertebral.

small crustacean. In a wider sense, the word is often loosely applied to various small invertebrates.

Between crura; -- applied especially to the interneural plates in the vertebral column of many cartilaginous fishes.

Between spines; esp., between the spinous processes of the vertebral column.

ny animal substance entering into the composition of the skeleton of sponges, and other invertebrates; -- called also keratode.

The lowest class of Vertebrata, including only the Amphioxus. The heart is represented only by a simple pulsating vessel. The blood is colorless; the brain, renal organs, and limbs are wanting, and the backbone is represented only by a simple, unsegmented notochord. See Amphioxus. [Written also Leptocardii.]…

ning small, calcareous concretions (otoliths). They are found in many Medusæ, and other invertebrates, and are supposed to be auditory organs.

A very large glandular and vascular organ in the visceral cavity of all vertebrates.