Mr. Stevens observed that Eunostus Gueinzii was stated hy M. Gueiiizius (o be 

 Docturnal in its habits, and this appeared to be generally the case with pale-coloured 

 insects : the pale Megacephala taken by Mr. Bates on the Amazon was said by him 

 to be a strictly nocturnal species. 



Mr. Smith observed, in corroboration of this theory, that the pale-coloured Vespa 

 Doryloides, Sauss., lately sent home by Mr. Wallace from Borneo, was said to be 

 found at night only, which was the more interesting as no other species of wasp was 

 yet known to be nocturnal. 



The following notes, which accompanied the collection exhibited by Mr. Stevens, 

 were communicated by M. Gueinzius: — 



On the Habits of Paiissida, ^c. 



" Except the specimens of Paussidae which have been attracted by candle-light, I 

 have never found a specimen elsewhere than in ants' nests, except one, and that anew 

 species, in this collection, which I found in the hot sunshine, sitting upon a blade of 

 grass, no doubt quite accidentally. They all live with sjiecies of ants which are car- 

 nivorous: Cerapterus, Pleuropterus and Pentaplatarthrus with different larger species, 

 but the true Paussi seem to live only with our small species ; at least I have found P. 

 cuctillatus, P. Dohrnii, P. Latreillii, P. Sliuckardii, and three other species in the 

 collection, all with one and the same species. 



" One night last summer I heard a slight tap on a window-pane, as from a grain 

 of gravel : upon going out with the candle I found it was a Paussus (similar to 

 Dohrnii), of which I had not seen a specimen for some years: not half an hour after- 

 wards I heard the same sound on the same window, and found a second specimen. 

 Although I did not observe the sex, tliere is little doubt that the first specimen was a 

 female, and the second a male. In a number of instances I have observed that the 

 females of Coleoptera move some time before the males. I observed one morning a 

 female Eudicella Smithii settle on a branch of a shrub before my door; not half an 

 hour after I had removed it a male had settled on the very same spot. An enormous 

 female Sternotornis niveisparsa (attracted by the candle) will strike the window so as 

 nearly to break the pane, when some time after the smaller-sized male will arrive at 

 the same window. In the same way, and under the same circumstances, I have ob- 

 tained two rare species of smaller Scarites, always in pairs; and so it appears that 

 these beetles are able to trace the flight of the opposite sex through the air, a good 

 while after it has passed. Paussi apjiear in the month of November, and last during 

 the whole season until April: their caustic juice is squirted out of the sides of the 

 abdomen ; part of it evaporates immediately as a blue smoke, distinctly visible by sun- 

 light; the remainder covers both sides of the elytra, and remains as a whitish or pale 

 yellow unctuous matter. I have repeatedly found P. Latreillii in the act of copulation 

 in ants' nests. The specimens are nearly always found in the part of the nest where 

 the eggs and pupae are deposited ; and although I have never yet observed a Paussus 

 in the act of feeding, yet, from the great and mysterious attachment which the ants 

 show them, I am inclined to believe that they feed upon the spoil which the ants con- 

 vey into the nests, rather than upon their eggs or pupse : I believe, likewise, that the 

 eggs of the Paussi are there deposited and bred, and it is not impossible that their 

 larvffi are fed by the ants as their own offspring. The sunny sides of the margins of 

 forests are the places where Paussi are generally met with ; a piece of old dry wood is 



