494 bulletin: museum of comparative zoology. 



but the differences of structure and habit seem to me to be sufficient 

 to entitle it to the rank of a species, as it was originally described by 

 Adlerz. According to this observer it does not build mound-nests 

 Uke the typical exsccta and its subspecies and varieties but resembles 

 F. truncicola in establishing its formicaries in rotten stumps or logs 

 which it banks with fine vegetable detritus. 



Fusca Group. 



80. F. FUSCA FUSCA Linne. 



F. fusca Linn6, Syst. nat. ed. 10, 1758, 1, p. 580; Fauna Suec, ed. 2, 1761, 

 p. 426; deGeer, Mem. hist, ins., 1771, 2, p. 1, pi. 42, figs. 12-15; Fabri- 

 cius, Spec, ins., 1781, 1, p. 490; Mantissa ins., 1787, 1, p. 308; Olivier, 

 Encycl. meth. insect., 1791, 1, p. 493; Fabricius, Ent. syst., 1793, 2, 

 p. 352; Latreille, Essai hist, fourmis France, 1798, p. 39, ^ 9 c?; Hist, 

 nat. fourmis, 1802, p. 159, pi. 6, fig. 32, e ^ 9 cf ; Fabricius, Syst. Piez., 

 1804, p. 399; Latreille, Gen. Crust, ins. 1809, 4, p. 126; Lepeletier, Hist, 

 nat. insect. Hymen., 1836, 1, p. 205, S 9 cf ; West wood, Introd. mod. 

 class, insects, 1840, 2, Synop., p. 83; Nylander, Acta Soc. Fennica, 

 1846, 2, p. 917, 919, ^ 9 d^, pi. 18, fig. 23; Ibid., 1849, 3, p. 27, 30; 

 Forster, Stettin, ent. zeit., 1853, 14, p. 141; F. Smith, Trans. Ent. soc. 

 Lond., 1855, ser. 2, 3, p. 104, ^ 9 c?, pi. 9, fig. 15; Mayr, Verh. Zool. 

 bot. ver. Wien, 1855, 5, p. 346, ^ 9 cf ; Nylander Ann. sci. nat. Zool., 

 1856, ser. 4, 5, p. 65, ^ 9 d", F. Smith, List Brit. anim. Brit, mus., 

 1858, pt. 6, p. 5, pi. 3, fig. 14; Meinert, Natur. abh. Dansk. vid. selsk., 

 1860, ser. 5, 5, p. 44, ^ 9 cf; Mayr, Europ. Formicid., 1861, p. 47-49, 

 y 9 c?; Taschenberg, Hymen. Deutschl., 1866, p. 239; Forel, Denks. 

 Schweiz., gesell. naturw., 1874, 26, p. 53, 56, 58, 356, ^ 9 d"; Bull. Soc. 

 Vaud. sci. nat., 1875, ser. 2, 14, p. 60; Lubbock, Journ. Linn. soc. Zool., 

 1877, 13, p. 217, pi. 17, fig. 3; Ern. Andre, Spec. Hymen. Europe, 1882, 2, 

 pt. 14, p. 182, 186, 190, pi. 5, fig. 12, ^ 9 cf ; Adlerz. Bih. Svensk. vet. 

 akad. Handl., 1886, 11, p. 286, 290, ^ 9 &] Wasmann, Deutsch. ent. 

 zeitschr., 1887, 31, p. 109; Dalla Torre, Catalog. Hymen., 1893, 7, p. 196; 

 Ruzsky, Formicar. Imper. Ross., 1905, p. 373, 1 fig.; Emery, Deutsch. ent. 

 zeitschr., 1909, p. 193, ^ 9 cf ; Ibid., 1912, p. 672. 



F. fusca var. glacialis Wheeler, Bull. Amer. mus. nat. hist., 1908, 24, p. 624, 

 ^ 9 d. 



Worker, Length 4-6.5 mm. 



Body rather slender. Head longer than broad, narrower in front 

 than behind, with straight posterior and lateral borders. Eyes large. 

 Mandibles 8-toothed. Clypeus sharply carinate its entire length, 



