Hip`po*cam"pus (?), n. [L., the sea
horse, Gr. &?; a hippocampus (in senses 1 and 2); "i`ppos
horse + &?; to bend.] 1. (Class. Myth.) A
fabulous monster, with the head and fore quarters of a horse joined
to the tail of a dolphin or other fish (Hippocampus
brevirostris), -- seen in Pompeian paintings, attached to the
chariot of Neptune. Fairholt.
2. (Zoöl.) A genus of lophobranch
fishes of several species in which the head and neck have some
resemblance to those of a horse; -- called also sea
horse.
&fist; They swim slowly, in an erect position, and often cling to
seaweeds by means of the incurved prehensile tail. The male has a
ventral pouch, in which it carries the eggs till hatched.
3. (Zoöl.) A name applied to
either of two ridges of white matter in each lateral ventricle of the
brain. The larger is called hippocampus major or simply
hippocampus. The smaller, hippocampus minor, is called
also ergot and calcar.
