I never had seen the imago of this species until the present year, and never saw the larva before 1896. Mr. Bruce tells me that it is a common species in parts of the Southern States, and that the eggs are laid in clusters, and the caterpillars are gregarious. In this paper I give simply my own observations. Early in August, 1896, I was asked what caterpillars were defoliating in Catalpa trees at Charleston, W. VA. It was said that some trees were completely stripped. I was unable to answer the question, as no caterpillar was shown to me. On my return home, I looked at my own Catalpa trees, and the first one that I happened on gave me a score or more of larva, one or two on a leaf, on the lower leaves of the tree. These larvae were three to four inches long, and evidently had passed their last moult. One young tree, perhaps ten feet in height, with a top six feet in diameter, had been completely stripped of leaves. I found a single caterpillar of Catalpœ on it, to shown what had done the mischief. I put the larvæ into a large flowerpot trvo-thirds filled with earth, and got, in a few days, some forty pupæ. Supposing these would go over to next year, I buried a few, and sent the rest to Mr. Bruce. In about two weeks he discovered that the imagoes had come out of his pupæ, and on examining mine the same result appeared.