42. "Of limpets," says Diphilus, "some are very small, and some are like oysters. But they are hard, and give but little juice, and are not very sharp in taste. But they have a pleasant flavour, and are easily digested; and when boiled they are particularly nice. But the pinnæ are diuretic, nutritious, not very digestible, or manageable. And the ceryces are like them; the necks of which fish are good for the stomach, but not very digestible; on which account they are good for people with weak stomachs, as being strengthening; but they are difficult to be secreted, and they are moderately nutritious. Now the parts of them which are called the mecon, which are in the lower part of their bellies, are tender and easily digested; on which account they also are good for people who are weak in the stomach. But the purple-fish are something between the pinna and the ceryx; the necks of which are very juicy, and very pleasant to the palate; but the other parts of them are briny, and yet sweet, and easily digestible, and mix very well with other food. But oysters are generated in rivers, and in lakes, and in the sea. But the best are those which belong to the sea, when there is a lake or a river close at hand: for they are full of pleasant juice, and are larger and sweeter than others: but those which are near the shore, or near rocks, without any mixture of mud or water, are small, harsh, and of pungent taste. But the oysters which are taken in the spring, and those which are taken about the beginning of the summer, are better, and full, and have a sort of sea taste, not unmixed with sweetness, and are good for the stomach and easily secreted; and when boiled up with mallow, or sorrel, or with fish, or by themselves, they are nutritious, and good for the bowels.