Fig. 1.

Left: The numbers of species described per 5-y interval for three selected regions increase broadly exponentially over time. Right: Corrected for the number of taxonomists involved in their description, most regions are like Mexico and Central America in showing a pronounced decrease in the rate of species described per taxonomist, leading to a modeled increase that averages 15% more species than at present. For both the region from Ecuador to Peru and the Northern Palearctic, however, there is no decrease, suggesting that considerable numbers of species are still missing from the taxonomic catalog. In both figures, plotted data start when the region has accumulated at least 40 endemic species.