them alone, and never, that we know of, attack any other. Thus that of the Privet Hawk or Sphinx Ligustri of Linnæus, that of the Elephant Hawk or Sphinx Elpenor of the same author, &c. are always found to yield particular kinds of Ichneumons. Others, indeed, attack any kind of caterpillar belonging to the farinaceous-winged tribe; and, as I observed above, if not too powerful and strong for them, will there deposit their eggs. "If the egg is laid on the body of the caterpillar, and not within it, a few days, by the warmth of the sun, ripens it to maturity; and then the young destroyer, directed by nature, eats its passage through the under-side of the egg, and passes into the body of the caterpillar, but if the egg is discharged into its body, it there ripens, unseen, to maturity. In either case, it lives on the substance or juices of its intestines; thriving and increasing in bulk, in a proportion equal to the creature it is doomed to kill. The caterpillar, also, notwithstanding its having thus received the means of a slow but certain death, increases in size, and, to outward appearance, in health; arriving to the period when it is to undergo its metamorphosis, and become a Chrysalis, in as much strength and vigour as any other of the species: but when the time arrives for its enlargement into its complete state, and to become a moth or butterfly, the Ichneumon makes its appearance; having arrived to its time of completion within the body of its supporter, and exhausted its juices by the nourishment drawn from it, leaving behind it a dry empty shell, in the form of a chrysalis. "In this manner many of these Ichneumons exist. Others, when arrived to maturity, having lived within the bodies of the caterpillars, as described, eat their way out through its sides, and, crawling to a small distance, form round themselves cases of a substance like silk; wherein, having lain a few days, they quit their prisons in the shape of very small flies, some having two wings, others four."--Vide Goedartius, Albin, Wilks, Harris, &c. POLISTES ANNULARIS. Plate XLIII. fig. 6. ORDER: Hymenoptera. SECTION: Diploptera. FAMILY: Vespidæ, _Leach._ GENUS. POLISTES, _Fabr._ Vespa, _Linn. Drury._ POLISTES ANNULARIS. Fusca; genubus, antennarum apicibus margineque primi segmenti abdominis flavis. (Long. Corp. 1 unc.) SYN. Vespa annularis, _Linn. Syst. Nat._ 1. 2. 950. 9. _Fabr. Syst. Piez._ 271. 3. (Polistes a.) Vespa cincta, _Drury, App. vol._ 2. HABITAT: Virginia (_Drury_).