148 BRITISH ANTS. 



XV (1896) 32 ; Johnson Irish Nat. 6 57 (1897) 33 ; Cuthbert Irish Nat. 7 67 34 

 209 35 (1898) ; Morley Hym. Suffolk 2 2 (1899) 36 ; Saunders Ent. Mo. Mag. 

 36 14 (1900) 87 ; Donisthorpe Ent. Rec. 12 176 (1900) 38 ; Vic. Hist. Cumber- 

 land 1 103 (1901) 39 ; Malloch Fauna, Flora, Geol. Clyde Area 219 (1901) 40 ; 

 Carter Ent. Mo. Mag. 37 67 (1901) 41 ; Donisthorpe Ent. Rec. 14 16 (1902) 42 ; 

 Saunders Irish Nat. 12 68 (1903) 43 ; Jordain Trans. N-Staff. Nat. Field 

 Club 17 82 (1903) 44 ; Vic. Hist. Sussex 1 131 (1905) 45 ; Harwood Ent. Mo. 

 Mag. 41 117 (1905) 46 ; Vic. Hist. Berks. 1 76 (1906) 47 ; Vic. Hist. Cornwall 



1 182 (1906) 48 ; Rothney Ent. Mo. Mag. 42 14 (1906) 49 ; Donisthorpe Ent. 

 Rec. 18 317 (1906) 50 ; Escherich Ameise 218 (1906) 51 ; Frisby Proc. Holmes- 

 dale NH. Club 1906 74 52 ; Vic. Hist. Kent 1 116 (1908) 53 ; Donisthorpe 

 Trans. Leicester Lit-Phil. Soc. 12 227 (1908) 54 ; Morley Ent. Mo. Mag. 44 

 215 (1908) 56 ; Silverlock Nat. 1910 13 56 ; Wasmann Biol. Centralb. 30 

 494-495 (1910) 57 ; Donisthorpe Ent. Rec. 23 11-12 (1911) 58 ; Orr Irish 

 Nat. 20 76 (1911) 59 ; Donisthorpe Entom. 44 390 (1911) 60 : Ent. Rec. 24 

 5 (1912) 61 ; Evans Scot. Nat. 1912 107 62 ; J. Taylor Ent. Rec. 24 65 (1912) 63 ; 

 Donisthorpe Ent. Rec. 25 62-63 (1913) 64 : Rep. Lancs-Chesh. Ent. Soc. 

 36 1912 54 (1913) 65 ; Hallett Trans. Cardiff Nat. Soc. 45 3 (1913) 66 ; Crawley 

 and Donisthorpe Int. Ent. Cong. Oxford 2 1912 20 (1913) 67 ; Donisthorpe 

 Ent. Rec. 26 38 (1914) 68 ; Crawley Ent. Rec. 26 91, 95, 97 (1914) 69 . 



^ Reddish yellow with the head, club of antennae, and dorsal surface of the 

 gaster darker, occasionally the whole body is yellow, the darker parts being only 

 slightly darker, or brown with the darker parts brownish black. 



Head longitudinally striate ; clypeus somewhat concave, smooth and 

 shining ; antennae eleven- jointed, club blackish. Thorax more or less rugose ; 

 suture between mesonotum and epinotum distinct ; epinotal spines moder- 

 ately long. Petiole and post-petiole very finely rugose ; gaster smooth and 

 shining. Legs : tibiae with erect hairs. Long. 3-4-4-5 mm. (3-3-3*7 mm. 

 teste Forel.) 



$ Very like the ^, generally darker in colour, mesonotum often red with 

 black patches. 



Antennae eleven- jointed. Tibiae with erect hairs. Wings white, the 

 radial cell open. Long. 4-4-8 mm. (3-5-4-2 mm. teste Forel.) 



$ Black, or brownish black ; tibiae and tarsi, and the articulations of the 

 legs yellow. 



Head rugose ; antennae twelve- jointed, the joints of the funiculus only 

 broader at the apex, and not forming a distinct club, second joint of funiculus 

 longer than the scape. Thorax rugose. Petiole finely longitudinally striate ; 

 post-petiole and gaster smooth and shining. Wings as in the <j>. Long. 4-8-5 

 mm. (3-7-4-8 mm. teste Forel.) 



Original description of Formica acervorum Fabricius [Ent. Syst. 



2 358 (1793)] :- 



" F. rafa capite abdomineque nigris, thorace postice bispinoso, petiolo 

 binodi. 



Habitat in Daniae nemoribus Mus. Dom. de Sehestedt. 



Nimis certe aflinis F. tuberum. Caput iiigrum antennis mandibulisque 

 runs. Thorax rufus dorso nigro postice spinis duabus porrectis, validis, 

 acutis. Petiolus ferruginous, binodis. Abdomen glabrum, atrum, immacula- 

 tum. Pedes ferruginei." 



Habitat. 



Leptothorax acervorum ranges over the whole of Europe except 

 in the extreme south, and Ruzsky records it from Siberia and 

 Turkestan. 



Its distribution in the British Isles is as follows : 



Cornwall, E. : Near Looe 48 . 



