or SAND-EEL, in ichthyology, a genus of fishes belonging to the order of apodes. This fish resembles an eel, and seldom exceeds a foot in length. The head of the ammodytes is compressed, and narrower than the body; the upper jaw is larger than the under; the body is cylindrical, with scales hardly perceptible. There is but one species of the the ammodytes, viz. the tobiamus, a native of Europe. This fish gathers itself into a circle, and pierces the sand with its head in the centre.