A friend, Professor Smith of Sackville, New Brunswick, has called my attention to the fact that the term “Wallace's Line,” as defined in the Century Dictionary, is employed by other scientists than mathematicians. In these days, when increasing attention is paid to the nomenclature of lines and curves, it may be of interest to add here a brief quotation from the dictionary: “Wallace's Line [so named after Alfred R. Wallace, who defined it] in Zoögeography, a line assumed to separate the Indomalayan from the Austromalyan Zoological region or faunal area. It passes between Borneo and Celebro, through the Strait of Macassar. Southward between Bali and Lombok, northeastward between Mindanao and Gilolo. This line divides the shallow waters of the Indomalayan region from the much deeper Austromalayan seas; and the character of the fauna is quite different on the two sides of it.”