78 BULLETIN" 826, U. S. DEPARTMENT OF AGRICULTURE. 



forms generally are of a yellowish, or brownish-yellow color, some- 

 times a milk white. Wax-secreting plates are present but they 

 are not developed to the same extent as are those of the Prociphilini. 

 The cornicles are lost entirely and the region where these usually 

 occur is occupied by wax plates. In some species the wax areas are 

 reduced. Some species are armed with fine hairs, whereas others 

 are almost entirely smooth. The eyes in the apterous forms are 

 composed of three facets. The alate forms have rather short, thick 

 antennas with somewhat oval sensoria. Three genera compose the 

 tribe and these may be separated as follows: 



Key to the Genera of the Fordixi. 



1. Antenna? of the alate form composed of five segments Forda. 



Antennas of the alate form composed of six segments 2. 



2. Sensoria of the antennae of the alate form small and scattered over most 



of the segment, a central triangular wax plate on the thorax; apterous 



form with six-segmented antennas Paracletus. 



Sensoria of the antennas of the alate form larger and more evenly placed; the 

 sensoria sometimes extending evenly across the segment. Apterous form 

 with five-segmented antennas, sometimes with six segments present Geoica. 



Genus FORDA Heyden 



Plate XIII, V-AA. 



1837. Forda Heyden, Mus. Sinkbg., v. 2, p. 291. 



1841. Rhizoterus Hartig. Zeit. Ent., v. 3, p. 363. 



1849. Smynthurodes Westwood, Gardener's Chron., p. 420. 



1896. Pentaphis Horvath, Wien. Ent. Zeit., v. 15, p. 2. 



1909. Pentaphis Del Guercio, Rivist. Patol. Vegetale, n. s., v. 3, p. 332. 



1914. Reciinasus Theobald, The Entomologist, v„ 47, p. 28. 



In 1837 Heyden erected his genus Forda, the type of which is 

 formicaria Heyden. In 1896 Horvath erected his genus Pentaphis 

 with marginata Koch as a type, while Del Guercio in 1909 used 

 trivialis Pass, as the type of a genus of the same name. Specimens 

 of marginata Koch from Horvath prove that this species in every 

 respect is similar to the type of the genus. Pentaphis, therefore, will 

 become a synonym of Forda. Likewise specimens of trivialis show 

 that this species belongs in the same genus. In 1841 Hartig erected 

 the genus Rhizoterus, the type of which is vacca. According to 

 Lichtenstein this species is a synonym of formicaria Heyden, and 

 Rhizoterus also, then, becomes a synonym. 



In 1914 Theobald erected his genus Rectinasus with his buxtoni 

 as type. He based his genus on the proportions of the antennal 

 segments, their length, and the length of the beak. The writer is 

 opposed to basing genera on the proportions of the antenna! segments, 

 for in species in which these are of different proportions a very close 

 relationship is evident. This is also true of the beak. Many Ameri- 

 can species taken in ants' nests and as yet undescribed have beaks 

 ranging from small to longer than the body, but they are all evidently 



