There is a very small fish2495 that is in the habit of living among the rocks, and is known as the echeneis.2496 It is believed that when this has attached itself to the keel of a ship its progress is impeded, and that it is from this circumstance that it takes its name.2497 For this reason, also, it has a disgraceful repute, as being employed in love philtres,2498 and for the purpose of retarding judgments and legal proceedings—evil properties, which are only compensated by a single merit that it possesses—it is good for staying fluxes of the womb in pregnant women, and preserves the fœtus up to birth: it is never used, however, for food.2499 Aristotle2500 is of opinion that this fish has feet, so strong is the resemblance, by reason of the form and position of the fins.

Mucianus speaks of a murex2501 of larger size than the purple, with a head that is neither rough nor round; and the shell of which is single, and falls in folds on either side.2502 He tells us, also, that some of these creatures once attached themselves to a ship freighted with children2503 of noble birth, who were being sent by Periander for the purpose of being castrated, and that they stopped its course in full sail; and he further says, that the shell-fish which did this service are duly honoured in the temple of Venus,2504 at Cnidos. Trebius Niger says that this fish is a foot in length, and that it can retard the course of vessels, five fingers in thickness; besides which, it has another peculiar property—when preserved in salt, and applied, it is able to draw up gold which has fallen into a well, however deep it may happen to be.2505