176 Mr. Westwood on the Papilio Telamon, fyc. black, of which colour there is also a short longitudinal contiguous black streak. The inner margin of the fore wings in the male is emarginate in the middle. The wings are not nearly so long and narrow as in D. Horsfeldii, and they are slightly transparent, so that the large ocelli on the underside of the hind wings are slightly visible from above. The species is nearly allied to D. Catops, Bdv., D. W. & H. Gen. D. Lep. p. 325. XXI. On the Nest of Polistes Lanio, Fab. and a Parasite found therein, and on the Nest of a Social Wasp. By F. Smith, Esq. [Read 7 April, 1851.] John Mac Gillivray, Esq., Naturalist to Her Majesty's Ship Rattlesnake, lately presented to the British Museum the nest of a South American species of Polistes, which he says is very abundant at St. Salvador, where even in the streets it attaches its nest under the eaves of houses ; the species is the Polistes Lanio of Fabricius, and in all probability the Vespa Canadensis of Linnaeus ; a specimen of the species is preserved in the Banksian Cabinet. On examining the nest, I found it consisted as usual of a single comb of cells, having in the centre at the back a short footstalk, by which the nests are attached in their position ; the comb con-tained sixty-five cells, the outer ones being in an unfinished state, whilst twenty-two of the central ones had remains of exuviae in them, and one or two closed cells contained perfect insects ready to emerge ; about half a dozen of the wasps had the anterior portion of their bodies buried in the cells, in the manner in which these insects are said to repose. In one cell I observed the head of an insect evidently of a different species, it being black and shining. On extricating it, I discovered it to be a species of Tri-gonalys; I subsequently carefully expanded the insect, and it proved to be the Trigonalys bipustulatus, described by myself in the Ann. and Mag. of Natural History, vol. vii., 2nd Series, 1851, from a specimen captured at Para by Mr. Bates, now in the pos-session of William Wilson Saunders, Esq. The insect was not enveloped in any pellicle, nor had the cell been closed in any way; the wings were crumpled up at its side, as is usual in Hymeno-pterous insects which have not expanded them, proving satis-factorily that it had never quitted the cell, and that Trigonalys is the parasite of Polistes.