"Thousands of small amphibious flies," he says, "flit about in the air on the surface of lakes, and diving down into the water many feet, and even many fathoms, go to the bottom to lay their eggs, and only emerge from the water probably to die close by. We were fortunate enough to be present at a great fishing or harvest of the eggs, which, under the Mexican name of _hautle_ (_haoutle_), serve for food to the Indians, who seem to be no less fond of them than the Chinese are of their swallows' nests, which they resemble somewhat in taste; only the _hautle_ is far from commanding such high prices as the Chinese pay for their birds' nests, which for that reason are reserved entirely for the tables of the rich; while, for a few small coins, we were able to carry away with us about a bushel of the _hautle_, a portion of which, at our request, Mme. B---- was kind enough to prepare for us. "They dress these in different ways, but generally make a sort of cake, which is served up with a sauce, to which the Mexicans give a zest, as they do indeed to all their dishes, by adding to it _chilié_, which is composed of green pimento crushed. This is how the natives proceed when they are fishing for _hautle_: they form with reeds bent together a sort of fasces, which they place vertically in the lake at some distance from the bank, and as these are bound together by one of the reeds, the ends of which are so arranged as to form an indicating buoy, it is easy to draw them out at will. Twelve to fifteen days suffice for each reed in these fasces to be entirely covered with eggs, which they thus fish up by millions. The former are then left to dry in the sun, on a cloth, for an hour or more; the grains are then easily detached. After this operation, they are replaced in the water for the next hautle harvest." M. Virlet had attributed to flies the eggs of which we have been speaking. But in 1851 M. Guérin-Méneville having received, transmitted to him by M. Ghiliani, eggs of which _hautle_ is made, and some of the insects said to produce them, stated that the latter belonged to two different species. The one had been known a long time since under the name of _Corixa mercenaria_; M. Guérin-Méneville called the other _Corixa femorata_. The same entomologist discovered, among the eggs of these two species, other eggs of a more considerable size, and which he attributed to a new species of the genus _Notonecta_, about which we are now going to say a few words.