Natural-History Collectors. 3803 



ptera, especially of the genus Canthon, of which the prevailing species 

 were quite new* to me. 



" I reached this town, Aveyros, on the 23rd of June, and have re- 

 mained here busily occupied to the present time. It consists of only 

 fourteen houses, but is the residence of the commandant of the dis- 

 trict, whom I previously knew. The river here is strewn with islands, 

 which divide its breadth into several channels ; this breaks the force 

 of the swell and the winds, and renders travelling about in small boats 

 pleasant. The town is situated on a tract of low land, and the forest 

 offers nothing peculiar in the prevailing trees &c. from other districts. 

 From this cause, the great majority of the diurnal Lepidoptera are the 

 same as those I have met with in other places : but the diversity of 

 species, and profusion of insects generally, is greater than I have ob- 

 served elsewhere. Some of the species are old Para friends, such as 

 Papilio Vertumnus and Sesostris, Epicalia ancea, Nymphalis Sthene- 

 les, two species of Heterochroa, one of Paphia, four of lthomia, Lep- 

 talis locula, and a great number of the rarer Para Erycinidae. Others 

 are the same as the Tocantins species, particularly the beautiful sharp- 

 winged Papilio I had not yet met with except on the Tocantins. Ma- 

 ny are the same as those of Obydos, particularly the Eurygonae and 

 Heliconia Melpomene. Two only are Ega species, — one, the Calli- 

 thea Batesii (of which I have secured only one, a female, very perfect), 

 and one of the rarest of the Ega Cybdeles. I have enumerated nearly 

 300 distinct species of diurnal Lepidoptera seen here, including of 

 course those numerous species common everywhere. The new spe- 

 cies are in Leptalis, Heliconia, Eresia, Heterochroa, &c, and in 

 Eurygona, Calospilus, and other groups of Erycinidae. In all the 

 other orders the diversity is equally great, and the number of species 

 new to me far greater than in butterflies. 



" As to the blue and orange Megastomas, I never saw them in co- 

 pula nor in amoribus. All I can say is, that they are in equal abun- 

 dance in the same places, flying with vast rapidity, and settling upon 

 old logs, edges of canoes, &c, by the water-side. / think they are 

 male and female, especially as the blue appeared about fifteen days 

 before the red ; and I would recommend Mr. Westwood to look again 

 and see if he cannot detect a few pairs of minute spines at the apical 

 joints of the fore-tarsi in the red and not in the blue. I have no spe- 

 cimens here, and cannot therefore decide the question. The differ- 

 ence in the fore-legs of the sexes in Nymphalidae I found out myself, 

 several months ago, and have a long series of sketches made ; it exists 



