45 



of the genus Microcraniiim {Barm.). Amongst the seflinient I found also one or two 

 large handsome Buprestirlu;. Staphylini occur in less abundance, although there are 

 great numbers of minute [species clinging to portions of wood, and a few very large 

 species, as Piuophilus torosus, Er., a very large Stapliylinidi. The Pselaphidte are 

 also in vast numbers, clustering within the crevices of pieces of wood and rubbish cast 

 up by the waters. I could only find lime to select a few of the more curious species ; 

 one was a minute Articerus, some others belonged evidently to genera at present un- 

 known. There were many other large Coleoptera, of which only single specimens 

 occured, such as two very fine Priouidae, one, I think, a Mecosarthrou. Numbers of a 

 Macraspis also occurred, — a genus which I thought were exclusively day-flyers, and it 

 was a species which I had not yet taken in its place in the forest. There were also 

 many Coccinellce ; two Canlharides which I have never been able to meet with else- 

 where; several Anthici, Curculionides, Cassidce and other families of Coleoptera. 



" There are a few Hymenoptera, ants and one or two bees and wasps. 



" The Hemiptera were chiefly two or three species of Pachycoridse, very handsome 

 insects, especially one, an Angocoris, but these were rare, whilst a species of Canthe- 

 cona was in great abundance. 



"The greater part of the insects thus cast up by the waters of the lake were quite 

 dead, others nearly so, whilst many clinging to portions of wood and weeds were alive: 

 two or three hours of an equatorial sun soon dispersed the latter: of the former, the 

 large-bodied Lamellicornes became a prey to flocks of iusectivorous birds, especially 

 bands of little sandpipers ; they ate only the abdomen : the Carabides and Hemip- 

 tera they would not touch ; many of them remained entire for many days, others fell to 

 fragments after being exposed to the sun. The waters of the rivers at this season were 

 retreating, but the fragments of insects were covered by a stratum of blown sand, and 

 this may serve to explain the method by which masses of the bodies and mutilated 

 remains of insects become imbedded in fossiliferous strata. 



" This wholesale destruction of insect life does not occur frequently ; in fact I 

 have witnessed it on a large scale only once a year. On many sultry evenings, in the 

 fine season, numbers of insects are to be seen flying abroad, but the various conditions 

 required for the grand immolation do not combine frequently. I have found many 

 interesting Coleopterous insects by standing in a favorable place on the banks of the 

 river, and observing them as they pass ; it is necessary to have the clear western sky 

 in the background. The insects are very uncertain in their appearance ; it is not even 

 every sultry night that proves favorable ; they appear to be acted upon by atmospheric 

 conditions which we cannot ourselves appreciate or calculate. Many of the insects 

 taken flying in this way are the same as those found drowned on the beach, as related 

 above, especially the Scaritidse, the Polystichi, Heteromera, &c. ; but many others are 

 d iflferent, — for instance, many small Longicornes, especially Chrysoprasis, are eminently 

 day-insects. 



" One evening on the banks of the Amazons at St. Paulo I witnessed an extraor- 

 dinary flight of Coleoptera, almost all Scaritidse ; there was literally a shower of them 

 nearly all the same species — some twenty or thirty — which I had previously found at 

 Ega, on the beach. These insects are extremely difiicult to find in their proper habi- 

 tats; of the thirty or more species of Scaritidoe found flying in the evening, I have 

 not taken more than five or six in siiu, and those at roots of herbage in shady places. 

 Sometimes these nocturnal insects may be attracted by a lamp at night, placed in a 

 favorable place, but a prolific night rarely occurs ; in this way I have taken a great 



