Species of British Formicida. 1 25 



naliter striatulo ; alis totis albo-hyalinis, spinis metathoracis 

 mediocribus ; nodis parum scabris. 



Operaria. — Sordide rubra, sparse pilosula ; capite abdomineque 

 supra fuscescentibus ; capite longitudinaliter striatulo; thorace 

 nodisque petioli rugoso-scabriusculis, metathorace spinis medio- 

 cribus. 



Mas. — Niger, cinereo-pilosulus; tibiarum basi apiceque, tarsisque 

 dilute pallidis, metathoracis apice polito, utrinque angulatim 

 tuberculato ; alis lacteo-hyalinis. 



Formica acervorum, Fabr. Ent, Syst., ii. 358, 38, 5 > Syst. Piez. 



p. 407, 50. 

 Myrmica acervorum, Zett. Ins. Lapp., 451, 3, 2,^ ; Nyland. 



Adno. Men. Form., 936, 7, $, ?, $ ; 



Foerster, Hym. Stud. Form., 61,32; 



Curtis, Trans. Linn. Soc, xxi. 215, 6. 

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



Female. — Length 1|^ lin. Head elongate, subquadrate ; above 

 the insertion of the antennas, but not quite extending to the ver- 

 tex, fuscous ; the rest of the head pale ferruginous ; the three 

 apical joints of the antennas fuscous ; the thorax, legs and nodes 

 pale ferruginous ; the thorax indistinctly longitudinally striated, 

 slightly fuscous at the insertion of the wings; spines of the meta- 

 thorax short, stout and acute ; the first node sliglitly roughened 

 behind, the second smooth, or faintly sculptured. Abdomen ob- 

 long-ovate, dark fusco-ferruginous, pointed at the apex, and 

 sprinkled with pale glittering hairs. 



Worker. — Length ]| lin. This scarcely differs from the female 

 in anything but size, except in tlie usual compression of the sides 

 of the thorax, and in the absence of the ocelli ; the spines are 

 rather stouter and longer, and the second node is rather more dis- 

 tinctly sculptured with fine striae. 



Male. — Black, the tarsi and articulations of the legs pale testa- 

 ceous ; the entire insect is thinly clothed with long cinereous 

 pubescence; the antennae apparently 12-jointed ; the palpi minute, 

 pale testaceous; the mandibles truncate at their apex. 



This, like most of the small species, is rarely met with, I once 

 found a colony on Shirly Common, under the bark of a decaying 

 tree ; it consisted of one female and about fifteen workers. Mr. 

 Dale has taken it in the New Forest, at Glanvilles Wootton, and 

 at Lulworth. I have also received it from Scotland. 



