434 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
The specimens from Boulder, Colorado, represent a series from a single 
colony, the largest with a few suberect hairs on the tibiae, the medium 
sized and small workers without any, so that one is in doubt as to which 
subspecies they belong. I have not seen females and males of the 
true obscuripes and am inclined to believe that further study may show 
that both obscuripes and aggerans are really the same rather variable 
subspecies. Both build the same type of nest, a dome-shaped mound 
of twigs and other vegetable débris, often very coarse and very much 
like the nests of the European pratensis in size and shape. Formica 
obscuripes, like the typical aggerans, is peculiar to British Columbia and 
the Northwestern States, being best represented at altitudes between 
5,000 to 8,000 ft. 
30. F. RUFA OBSCURIPES var. WHYMPERI Forel. 
F. rufa st. obscuripes var. whymperi Forel, Ann. Soc. ent. Belg., 1904, 48, p. 
192° O° 
F. rufa obscuripes var. whymperi, Wheeler, Ants, 1910, p. 570. 
WorkKER. With the color and aspect of the darker forms of F. 
pratensis of Europe; front, vertex, occiput, and dorsum of pronotum 
and mesonotum blackish; with the same pubescence and sculpture, 
but with the sparse pilosity of obscuripes; tibiae without suberect 
hairs. 
Type LOcALITY.— British Columbia: Vermillion Pass, 5,000-6,500 
ft. (E. Whymper). 
This form seems to have been described from a single worker. 
I have not been able to recognize it among the material collected in 
British Columbia by J. C. Bradley and W. Wenman. 
31. F. TRUNCICOLA TRUNCICOLA Nylander. 
F. truncicola Nylander, Acta Soc. Fennica, 1846, 2, p. 907, 8 9; Ibid., 1849, 
°3, p. 26, 29, &; Forster, Hymen. stud., 1850, 1, p. 21, 9 @ (nec 8); 
Schenck, Jahrb. Ver. nat. Nassau, 1852, 8, p. 33, 139, 145,8 2 o&; 
Stettin. ent. zeit., 1853, 14, p. 160; Mayr, Verh. Zool. bot. ver. Wien, 1855, 
5, p. 334, 8 2 o&; Europ. Formicid., 1861, p. 46, 48, 8 @ o; Forel, 
Bull. Soc. Vaud. sci. nat., 1875, ser. 2, 14, p. 58; Mayr, Fedtschenko’s 
Turkestan. Formicid., 1877, p. 6; Ern. André, Spec. Hymen. Europe, 
1882, 2, pt. 14, p. 183, 187, 189, 8 @ @; Dalla Torre, Catalog. 
Hymen., 1893, 7, p. 213; Bingham, Fauna Brit. Ind., 1903, 2, p. 334; 
Forel, Ann. Mus. St. Petersbourg, 1904, 8, p. 385; Ruzsky, Formicar. 
Imper. Ross., 1905, p. 330, fig. 63, 64. 
