1919] Wheeler — A Singular Neotropical Ant 125 



agreeing with Fabricius' and Smith's descriptions oi filiformis and 

 cephalica, but also many workers agreeing perfectly with Forel's 

 description and with a cotype of biconvexa which he kindly gave 

 me many years ago. 



The genus Pseudomyrma, owing to the great number and varia- 

 bility of its species is one of the most difficult of ant-genera. As a 

 small contribution to the revision to which it must before long be 

 submitted I give a fuller description of the worker, female and male 

 of Ps. filiformis, with larger and more detailed and I trust also 

 somewhat more accurate figures than those published by Smith. 



Pseudomyrma filiformis (Fabr.). 



Formica filiformis Fabricius, Syst. Piez. 1804, p. 405 9 • 

 Leptalea filiformis Erichson, Arch. f. Naturg. 5, 1839, p. 309 9 . 

 Pseudomyrma cephalica F. Smith, Trans. Ent. Soc, London (2) 3, 



1855, p. 168, PI. 13, Figs. 12-17, ^ 9 c^ ; F. Smith, Cat. 



Hym. Brit. Mus. 6, 1858, p. 155, PI. 10, Figs. 25, 26 § 9 cf ; 



Roger, Berlin, Ent. Zeitschr. 6, 1862, p. 289. 

 Pseudomyrma filiformis Mayr, Verhand. Zool. bot. Gps. Wien, 



1863, p. 452 9 ; Roger, Berhn, Ent. Zeitschr. 1863, p. 24 9 ; 



Mayr, Sitzb. Akad. Wiss. Wien 61, 1870, p. 407 9 ; Dalla 



Torre, Cat. Hym. 7, 1893, p. 56; Forel, Sitzb. Bayr. Akad. 



Wiss. 1911, p. 278, 9 ; Forel, Biol. Centr. Amer. Formicid. 



1899-1900, p. 86 9 • 

 Pseudomyrma biconvexa Forel, Biol. Centr. Amer. Formicid. 1899- 



1900, p. 95, PI. 4, Fig. 10 g ; Forel, Ann. Soc. Ent. Belg. 50, 



1906, p. 229 y ; Forel, Sitzb. Bayr. Akad. Wiss. 1911, p. 277 



S ; Forel, Mem. Soc. Ent. Belg. 20, 1912, p. 30 S . 

 Worker (Fig. 1). Length 4.5-5.8 mm. 



Head about 1| times as long as broad, subelliptical, with straight 

 posterior border and evenly convex sides, scarcely narrower in 

 front than behind; eyes about half as long as the sides, in front of 

 the middle, rather flat. Mandibles with convex external border, 

 apical border with two large terminal and four small basal teeth, 

 the basal border with three small separated teeth. Clypeus short, 

 emarginate on each side, with a short, subrectangular median lobe. 

 Frontal carinae short, closely approximated; frontal groove absent. 

 Antennae short, scapes scarcely reaching the middle of the internal 



