1929] The Ant Genera Gesomyrmex and Dimorphomyrmex 11 
Extinct Species. 
Gesomyrmex hoernesi Mayr. Baltic Amber. 
Gesomyrmex hoernesi Mayr, Beitr. Naturk. Preuss. 1, 1868 p. 
52, Fig. 38 to 41, worker minima; not the male; Dalla 
Torre, Catalog. Hymen. 7, 1893 p. 176; Ern. Andre, Bull. 
Soc. Zool. France 20, 1895 p. 82 ; Handlirsch, Foss. Insekt. 
1908 p. 859; Wheeler, Ants, etc. 1910 p. 170, Fig. 100; 
Wheeler, Schrift. physikal-okonom. Gesell. Konigsberg 
55, 1914, p. 108, Fig. 53, worker minima. 
Dimorphomyrmex theryi Emery, Bull. Soc. Ent. France 1905 
p. 188 Fig. 1, worker maxima; Handlirsch Foss. Insekt. 
1908 p. 868, worker maxima; Wheeler, Ants, etc. 1910 
p. 173, Fig. 98, worker maxima; Wheeler, Psyche 17, 
1910 p. 132; Wheeler, Schrift. physical-okonom. Gesell. 
Konigsberg 55, 1914, p. 104, Fig. 50, worker maxima. 
Dimorphomyrmex mayri Wheeler, ibid. p. 106, Fig. 51, worker 
media (large). 
Gesomyrptex annectens Wheeler, ibid. p. 107, Fig. 52, worker 
media (small). 
Prodimorphomyrmex primigenius Wheeler. Baltic amber. 
Prodimorphomyrmex primigenius Wheeler, Schrift. physikal- 
okonom. Gesell. Kdnigsberg 55, 1914, p. 112, Fig. 54, 
worker. 
Sicelomyrmex corniger (Emery) Sicilian amber. 
Gesomyrmex corniger Emery, Mem. 1st. Bologna (5) 1, 1891, 
p. 581, Figs. 33-35, worker; Wheeler, Ants, etc. 1910, 
Fig. 101, worker. 
Sicelomyrmex corniger Wheeler, Schrift. physikal-okonom. 
Gesell. Konigsberg 55, 1914, p. Ill, worker; Wheeler, 
The Social Insects, etc., 1928, Fig. 27, worker. 
The affinities of Gesomyrmex and Dimorphomyrmex to 
other Formicine genera have been discussed by Forel and 
Emery. In his revision of the subfamily Formicinse (1925), 
