This genus of Orthoptera is confined almost entirely to North America, where it is represented by twenty or more species. Joseph Redtenbocher in his “Monographie der Conocephaliden,” published in 1891, united Orchelimum, Serv., to Xiphidium, Serv. This action seems scarcely justified, as the two groups are quite as distinct as many other Orthopteran genera, and Redtenbocher's authority has not been generally recognized in this country. The species are distinguished with difficulty and the descriptions are widely scattered. These considerations have led me to attempt to make a key for their identification. It is quite possible that some of the species indicated are synonymous, but I am inclined to believe that all I have recognized are good, and I believe there are a considerable number undescribed. Many forms which differ from each other by very few structural differences are distinguished by some peculiarity of song or habit or habitat, and it is certain that a considerable number of them have been overlooked.