MYRMICA ACERVORUM. 29 



name " graminicola" I think it right to adopt Nylander's name. 

 I have never found a colony of this species all my examples, 

 eight in number, have been picked up singly. The late Mr. 

 Wing gave me a winged female which he took in his garden at 

 Lambeth. I have taken it on the wing in the month of Sep- 

 tember. A single specimen of the worker was taken at Ply- 

 mouth by Mr. Reading. The male is not known : Dr. Nylander 

 only describes the worker, Dr. Mayr the worker and female. 

 Mr. Janson found this species in company with Formica fuligi- 

 nosa. 



LEPTOTHORAX, Mayr. 



The maxillary palpi 5 -jointed ; the labial palpi 3-jointed ; the 

 female and worker of nearly the same size ; the pubescence on 

 the body above has the hairs clavate, narrowed at their base ; 

 the club of the flagellum 3-jointed. 



8. Myrmica (Leptothorax) acervorum. 

 F&mina. Sordida, pallide rubida, sparse pilosula ; capite, tho- 



race abdomineque supra fusco-nigricantibus ; capite longitu- 



dinaliter striatulo ; alis albo-hyalinis, nervis et stigrnate pal- 



lidis ; spinis metathoracis mediocribus. 

 Operaria. Sordide rubra, sparse pilosula ; capite abdomineque 



supra fuscescentibus ; capite longitudinaliter striatulo ; thorace 



nodisque petioli rugoso-scabriusculis. 

 Mas. Niger, nitidiusculus ; tibiarum basi apiceque tarsisque 



pallidis ; metathoracis apice polito, utrinque angulatim tuber- 



culato ; alis lacteo-hyalinis. 



Formica acervorum, Fabr. Ent. Syst. ii. 358. 38 ; Syst. Piez. p. 407. 



50. 

 Myrmica acervorum, Zett. Ins. Lapp. p. 451. 3. 



Nyl. Adno.Mon. Form. Bor.Eur.y. 936. 7 ; Addit.Adno.^.l^l ; 



Form. Fr. et d'Alger. p. 89. 16. 

 Foerst. Plym. Stud. Form. p. 61. 32. 

 Schenck, Beschr. Nass. Ameis. p. 97. 

 Smith, Brit. Form. p. 124. 8. 



Leptothorax acervorum, Mayr, Form. Austr. p. 164. 1. 

 Myrmica lacteipennis, Zett. Ins. Lapp. p. 452. 5 $ . 

 Myrmica graminicola, Latr. Hist. Nat. Fourm. p. 255 , nee $ 

 et $. 



Female. Length If line. Rufous; the head, thorax, and ab- 

 domen above, fuscous, nearly black ; the club of the antennae 

 and the middle of the femora fuscous ; the mandibles, base of 



