FORMICA FLAVA. 15 



detected, as it requires a high magnifying power to distinguish 

 the hairs. The female is readily known from the same sex of F. 

 flava by its head being as wide or rather wider than the thorax ; 

 in F. flava it is considerably narrower. The worker is difficult to 

 distinguish : the pubescent eyes, scape of the antennae, and the 

 tibiae are the best distinctions ; but even these are not to be 

 relied upon when examining large workers of F. flava, which are 

 also pubescent. The species is not uncommon, so that all the 

 sexes can be obtained from the nest. 



10. Formica flava. 



F&mina. Fusca, nitida, dense flavido-sericea ; antennis pedi- 

 busque pallidis ; alis hyalinis, basin versus parum infuscatis, 

 nervis et stigmate flavido-testaceis ; capite thorace angus- 

 tiore ; squama subovali, supra late obtuse angulatim emargi- 

 nata, 



Operaria. Flavo-testacea, lata, nitida, sericeo-micans sparseque 

 flavido-pilosula ; oculis minutis, ocellis minutissimis aut nullis ; 

 squama parva, subovali, supra rotundata vel truncata. 



Mas. Fusco-niger, nitidissimus ; palpis, antennarum flagellis, 

 pedum articulis et tarsis flavido-testaceis ; fronte media levis- 

 sime transversim subimpressa ; alis subhyalinis, nervis pallide 

 testaceis, quandoque pallide fuscescentibus ; squama subqua- 

 drata. 



Formica flava, De Geer, Ins. ii. 1089. 5. t. 42. f. 24-28. 

 Fabr. Ent. Syst. ii. 357. 34 ; Syst. Piez. p. 406. 44. 

 Latr. Hist. Nat. Fourm. p. 106. pi. 6. fig. 36, A ? , B $ , E $ . 

 Losana, Form. Piem. p. 331. 17. 

 St. Farg. Hym. i. 208. 9. 

 Nyl. Adno. Mon. Form. Bor. Eur. p. 922. 17 ; Form. Fr. et 



d'Alger. p. 69. 28. 

 Foerst. Hym. Stud. Form. p. 38. 17. 

 Schenck, Beschr. Nass. Ameis. p. 56. 

 Smith, Brit. Form. p. 108. 7. 

 Mayr. Form. Austr.p. 91. 24. 



Female. Length 3 lines. Fuscous ; the face below the insertion 

 of the antennae, the palpi, antennae and legs pale yellow- 

 testaceous ; clothed with a fine yellow silky pile ; the head 

 much narrower than the thorax; wings hyaline, faintly smoky 

 at their base ; the scale of the petiole widely but slightly emar- 

 ginate. Abdomen ovate, with its apex pale testaceous yellow. 



Worker. Length 1^-2 lines. Yellow ; the small workers pale 



