16 bulletin: museum of comparative zoology. Mr. Kusche at Fort Yukon, Nulato, and Rampart (64°-67° N. L.) are of unusual interest, because, with the single exception of the specimens of Leptothorax kincaidi taken by Mr. F. H. Whitney on the Upper Kugarok River, near Nome, and recorded in my paper on the mountain ants of western North America (Proc. Amer. acad. sci., 1917, 52, p. 512), no American ants had previously been found so far north. Fort Yukon, the remotest of the localities, is, in fact, situated on the Arctic Circle, which, I believe, may safely be taken as the extreme northern limit of our ant fauna. Owing to the important bearing of all the elements of the Alaskan biota on questions of geo-graphical distribution and on the question of a former Alaskan-Siberian land-bridge in particular, it seems advisable to publish a brief anno-tated list of the known Alaskan Formicidae together with a record of the various localities in which they were collected. 1. Myrmica brevinodis Emery var. sulcinodoides Emery. Pergande records this form from Sitka and says that the palest specimens in his series agreed exactly with those he saw from Hill City, South Dakota. The specimen from Homer, Alaska (A. Mehner) referred by me to the var. frigida Forel (Bull. Wise. nat. hist, soc, 1907, 5, p. 78) may be more properly referred to sulcinodoides. Indeed, I doubt whether frigida can be maintained as a distinct variety. Forel's var. whjmperi is also, in my opinion, a synonym of sulcino-doides Emery. The latter is known from higher elevations, up to 11,000 feet, in the Rockies of British Columbia, Utah,-Colorado, and New Mexico and in the Sierra Nevada. In the paper cited above I called attention to the peculiar greenish yellow color of the larvae of this ant and their oily luster. 2. Myrmica brevinodis var. alaskensis Wheeler. Recently described from workers taken at Seward, on the Kenai Peninsula by Mr. F. H. Whitney (Proc. Amer. acad. sci., 1917, 52, p. 503). Numerous specimens from two colonies found by Mr. Kusche at Fort Yukon and in the Pynaw Mts., near Rampart, also belong to this variety.
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