Basilisk (basiliscus, Laurenti), a genus of saurian reptiles of the family of iguanidce, inhabiting the northern parts of South America, the West Indies, and Central America. The genus is characterized by a thin triangular fold of skin rising vertically from the occiput and inclined backward, resembling in shape a Phrygian cap; the external edge of the posterior toes is bordered with a scaly serrated fringe; the back and tail are surmounted in the adult male by an elevated crest, supported on the spinous process of the vertebras, of varying height, and serrated; in one species this crest resembles the dorsal fin of a fish, while in the other it is merely a serrated scaly ridge; between the dorsal and caudal portions the crest is interrupted, and both are covered with thin scales disposed in series parallel to the spinous processes. Under the neck is a rudimentary angular crest, behind which is a well marked transverse fold. There are 5 or 0 teeth on each palatal bone, and 50 to 60 in each jaw, pointed and subcorneal, or compressed. It is distinguished from the iguana by the absence of femoral pores.

The head is covered with small many-sided ridged scales; the body above has rhomboidal ridged scales, arranged in transverse bands; the ventral scales are either smooth or ridged, according to the species. The limbs, especially the posterior, are very long, as are also the toes, which are slender and armed with nails; the body is nearly cylindrical, and the tail compressed and three times as long as the trunk. Two species are described. 1. The hooded basilisk (B. mitratvs, Daudin) has the above-mentioned cap and dorsal crest, and the ventral scales smooth, without transverse black bands on the back; the color above is yellowish brown, beneath whitish; the sides of the neck are leaden brown, and the throat is marked by longitudinal bands of the same color; sometimes there is a white band bordered with black on the sides of the neck and back; the length varies from 24 to 30 inches, of which the tail measures about two thirds. 2. The banded basilisk (B. vittatus, Wiegmann) differs from the preceding in having only a slight serrated crest along the back and tail, the ventral scales ridged, and black bands across the back; the general color is the same, with the exception of dark brown spots on the head, chest, and limbs, and 6 or 7 black bands extending across the back to the ventral surface.

This species was considered by Kaup as belonging to a different genus, which he called corythceolus; it formed the genus cedicoryphus of Wagler. Notwithstanding its forbidding appearance, the basilisk is a perfectly harmless animal; it feeds on insects, and lives principally on trees, which it climbs with great dexterity; it is supposed that the dorsal crest may serve to steady its motions as it springs from tree to tree. - The ancient poets imagined an animal, which they called basilisk, whose breath poisoned the air, whose glance was death, and whose presence was fatal to all other creatures, including man; they supposed it to have the form of a snake, and to be produced from the egg of a cock brooded upon by a serpent. The tziphoni of the Hebrew Bible is a true snake, improperly called basilisk in the Greek version, and in the English translation cockatrice, an animal as fabulous as the ancient basilisk.

Basiliscus mitratus.