278 Mr. F. Smith's Revision of 



Formica congerens, Nylander. 



Female. — Length 4 — 4J lines. Very closely resembling the 

 F. ru/a, but distinguished by being covered with a shining cinereous 

 pile ; the eyes pubescent, and the abdomen sub-opake ; not 

 shining as in F. nifa. 



Worker. — This is distinguished from the worker of F, rufa by 

 the same characteristicks as the female ; the pubescence on the 

 eyes is not discernible without a high magnifying power ; it is 

 however a very marked distinction. 



Male. — Black and covered with cinereous pile ; the head and 

 thorax covered with short black pubescence ; the scale of the 

 petiole sub-quadrate, slightly and widely emarginate above. 



Nylander says, this insect constructs similar nests to the 

 F. rufa, and, on being disturbed, emits the same strong odour of 

 formic-acid. 



The species was taken in Scotland by Mr. Foxcroft in 1846, at 

 Loch Rannoch ; — the male only has yet been captured. The 

 species is so very like the F. rufa that it would not be recog- 

 nized as a distinct species by any one but an Entomologist ; the 

 most striking difference being that it is thinly covered with hair, 

 F. rufa being naked. 



Formica brunnea, Latr., Nyland., Mayr, Schenck. 



Worker. — Length 1^ — 2| lines. Pale ferruginous, covered with 

 a fine cinereous silky pile; the abdomen obscure fusco-testaceous; 

 the head much wider than the thorax, with a distinctly impressed 

 line passing upwards from the clypeus, and extending nearly to 

 the vertex ; the scape rather paler than the head, the flagellum 

 faintly dusky above towards the apex ; the head slightly emargi- 

 nate behind. 



Female. — Length 4^ lines. Dark fuscous, with a fine cinereous 

 pile ; the mandibles, antennae and legs pale rufous ; the fiagellum 

 and femora slightly obscure ; the head as wide as the thorax ; the 

 scape of the antennae and the tibiae without pile or pubescence; 

 the basal half of the wings more or less fuscous ; an impressed 

 line on the front terminating at the anterior ocellus. 



Male. — Length 2 lines. Dark fuscous : the antennae, scape 

 and legs brown ; the flagellum and the articulations of the legs 

 pale testaceous ; a line on the front deeply impressed ; the eyes 

 not pubescent ; the scale of the peduncle emarginate ; the basal 

 half of the wings fuscous. 



