Note 4175 — BOOK V. AN ACCOUNT OF COUNTRIES, NATIONS, SEAS, TOWNS, HAVENS, MOUNTAINS, RIVERS, DISTANCES, AND PEOPLES WHO NOW EXIST OR FORMERLY EXISTED. (continued 2)
John Bostock translation
Apparently from the Greek κρυπτὸς, “concealed.” Stephanus Byzantinus says that it was so called because it was frequently hidden beneath the surface of the sea.