Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 21, 2025
The outer skin is very thin and delicate, naked, transparent, and composed of two different layers, a simple external stratum of cells, the epidermis, and a thin underlying cutis-layer. Along the middle line of the back runs a narrow fin-fringe which expands behind into an oval tail-fin, and is continued below in a short anus-fin.
The fin-fringe is supported by a number of square elastic fin-plates. The chorda develops no further, but retains its original simplicity throughout life. It is enclosed by a firm membrane, the chorda-sheath or perichorda. The perichorda forms a cylindrical tube immediately over the chorda, and the central nervous system, the medullary tube, is enclosed in it.
Word Of The Day
Others Looking