In the 'Magazine of Natural History,' 1838, p. 601, Mr. Westwood gives a very interesting account of the mode in which the ant-lion proceeds in the excavation of its pitfall, as witnessed by himself in specimens procured in the Parc de Belle Vue, near Paris, where, at the foot of a very high sand-bank, these pits were numerous, and of various sizes, but none exceeded an inch and a half or two inches in diameter, and two-thirds of an inch deep. "The ant-lions were of various sizes, corresponding to the size of their retreats. I brought many of them to Paris, placing several together in a box filled with sand. They, however, destroyed one another whilst shut up in these boxes; and I only succeeded in bringing three of them alive to England, one of which almost immediately afterwards (on the 23rd of July) enclosed itself in a globular cocoon of fine sand. The other two afforded me many opportunities of observing their proceedings. They were unable to walk forwards,--an anomalous circumstance, and not often met with in animals furnished with well-developed legs. It is generally backwards, working in a spiral direction, that the creature moves, pushing itself backwards and downwards at the same time, the head being carried horizontally, and the back much arched, so that the extremity of the body is forced into the sand. In this manner it proceeds backwards (to use an Hibernianism), forming little mole-hills in the sand. But it does not appear to me that this retrograde motion has anything to do with the actual formation of the cell, since, as soon as it has fixed upon a spot for its retreat, it commences throwing up the sand with the back of its head, jerking the sand either behind its back or on one or the other side. It shuts its long jaws, forming them into a kind of shovel, the sharp edges of which it thrusts laterally into the sand on each side of its head, and thereby contrives to lodge a quantity of the sand upon the head as well as the jaws. The motion is in fact something like that of the head of a goat, especially when butting sideways in play. In this manner it contrives to throw away the sand, and by degrees to make a hole entirely with its head, the fore legs not affording the slightest assistance in the operation. During this performance the head only is exposed, the insect having previously pushed itself beneath the surface of the sand; but when it has made the hole sufficiently deep, it withdraws the head also, leaving only the jaws exposed, which are spread open in a line, and laid on the sand so as to be scarcely visible. If alarmed, the insect immediately takes a step backwards, withdrawing the jaws; but when an insect falls into the hole, the jaws are instinctively and instantaneously closed, and the insect seized by the leg, wing, or body, just as it may chance to fall within the reach of the ant-lion's jaws. If, however, the insect be not seized, but attempts to escape, no matter in what direction, the