The insect inhabitants of Ecuador, like the birds, include a large number of genera and species, but no complete entomological survey of the country has ever been made, and our knowledge in this respect is insufficient to warrant a detailed description. In one ascent of Pichincha in 1880, Mr Whymper collected 21 species of beetles, all new to science, between 12,000 and 15,600 ft. elevation. On Cotopaxi, at elevations of 13,000 to 15,800 ft., 18 species of the genus _Colpodes_ were collected, of which 16 were new. This may be considered a fair illustration of the situation in Ecuador so far as natural history exploration is concerned. Of the Machachi basin, near Quito, which he calls a "zoologist's paradise," Mr Whymper writes (_Travels amongst the Great Andes of the Equator_): "Butterflies above, below and around; now here, now there, by many turns and twists displaying the brilliant tessellation of their under-sides ... May-flies and dragon-flies danced in the sunlight; lizards darted across the paths; and legions of spiders pervaded the grass, many very beautiful--frosted--silver backs, or curious, like the saltigrades, who took a few steps and then gave a leap. There were crickets in infinite numbers; and flies innumerable, from slim daddy-long-legs to ponderous, black, hairy fellows known to science as _Dejeaniae_; hymenopterous insects in profusion, including our old friend the bishop of Ambato (possibly _Dielis_), in company with another formidable stinger, with chrome antennae, called by the natives 'the Devil'; and occasional _Phasmas_ (caballo de palo) crawling painfully about, like animated twigs." This description refers to a fertile sub-tropical oasis on the partially barren plateau; below in the forested lowlands, where tropical conditions prevail, the numbers and varieties are many times greater. The Coleoptera are especially numerous; Mr Whymper took home with him 206 species which had been identified and described up to 1892, most of them from the uplands and most of them new to science. The total number of species in Ecuador is roughly estimated to be 8000. The Hymenoptera are also numerous, but less so than the Lepidoptera, with which the mountain slopes and sunny, open spaces seem to be literally covered. Of moths alone Mr Whymper took away with him specimens representing no less than 23 genera, with a probable addition of 13 genera more among his undescribed specimens, the largest of which (an _Erebus odora_) was 7¼ in. across the wings. Among the Diptera, which includes a very wide range of genera and species, are some of a highly troublesome character, though on the whole, Mr Whymper did not find the flies and mosquitoes so. His explorations, however, did not extend to the eastern region, where the mosquitoes are usually described by travellers as extremely troublesome. Sand-flies are common, and in the