2 THE ENTOMOLOGIST S RECORD. 



This is the usual form of the forewings in 2fi/niiica, but Nylander^ 

 describes and figures the forewing of a lacvinodis J in which the nerve 

 entirely divides the cell. I possess a <? of this species, taken by B. S. 

 Harwood at Sydmonton, in which the right forewing is exactly as in 

 Nylander's figure. Hallett sent me another ^ , which he had captured 

 near Cardifi", in which both forewings differ from the typical form. As 

 Wheeler'' remarks, the wings in ants are sometimes highly variable in 

 detail, even in J <? and ? ? reared from the same mother. 



Mi/nnica species, in common with some other ants, possess the 

 power of stridulating. In this genus it is caused by rubbing the post- 

 petiole against the first gastric segment, which is furnished with a file 

 composed of very tine transverse ridges. On this subject Wheeler'' 

 ■writes — " Stridulation, at least among the M>/)»iicinae .... is 

 an important means of communication, which Bethe has completely 

 ignored, and even Forel and other myrmecologists have failed to 

 appreciate. It readily explains the rapid congregation of ants on any 

 particle of food which one of their number may have found, for the 

 excitement of finding food almost invariably causes an ant to stridulate 

 and thus attract other ants in the vicinity. It also explains the rapid 

 spread of a desire to defend the colony when the nest is disturbed." 

 Swinton*^ records the stridulation of M. rufjinodis at Guildford, Sharp,° 

 in a paper on stridulation in ants, refers to M. scabrinudis, and Janet^° 

 describes the stridulation in Mynnica and gives some very beautiful 

 fio-ures of the apparatus by which the sound is caused. e 



The ants of this genus are common to the Nearctic and Palaearctic 

 regions. The geographical distribution of our species will be found 

 under each. Their British distribution has not yet been accurately 

 determined, but such as is known will be given in the hope that some 

 of our entomologists may be able to supply me with further records. 

 To mark the distribution in the British Isles I have adopted the 

 Watsonian system of counties and vice-counties. 



I shall also give a list of such myrmecophiles as have occurred 

 with each species, chiefly in Britain. I may here mention that species 

 of the genus Myrniica are the winter hosts of beetles of the genus 

 Atemeleti, s^ndi that the "wood-louse" Plati/artJirus huff'inanse[i[it, a,nd 

 the Collembola Cijphodeirus [Bcckia) albinus, are common to all our 

 species. Species of Mynnica both keep Aphides in their nests, and 

 also seek others, to milk them, on their proper food plants. These 

 plant lice are perhaps most cultivated by M. laevinodu. When these 

 ants caiiy each other, the one that is carried is not held under the 

 body as in Foniuca, but lies over the back with the ventral surface 

 uppermost, the legs and antennae being folded up. 



I have found the winged forms from June to October, but Sep- 

 tember is the usual month for the marriage flight. The winged sexes 

 at this time are often so numerous as to give the impression of a cloud 

 of smoke in the air. Farren White" records a flight of M. laevinodis 



■' Acta Soc. Fennicae, V. 2, 1846, p. 943, pi. xviii., fig. 4. 



6 Ants, 1910, p. 24. 



7 Science, N.S., xviii., 1903, p. 832. 



8 Ent. Mo. Mag., xiv., 1878, p. 187. 



9 Trans. Ent. Soc. Lond.. ii.. 1893, p. 206. 

 1" Ann. Soc. Ent. France, 1893, p. 161, etc. 



II Ants and Their Ways, 1895, p. 76. 



