an Essay on the British FormicidcB. 283 



Since I described this species under the name of Myrmica 

 laevigata I have had an opportunity of comparing it with speci- 

 mens sent by Dr. Mayr, it proves to be the " pall'idula" of his 

 Monograph. I have also taken three more examples of the worker 

 on a wall at Hampstead ; Mr. Parfit of Exeter has sent it to me, 

 he found it in a hothouse ; I have a suspicion that it is introduced 

 with plants or fruits, and will not prove to be indigenous. 



Subdivision 6. (Diphlorhoptrum, Mayr.) 



The workers very minute; the labial palpi 2-jointed; the 

 maxillary palpi 2-jointed; antennae of the worker 10-jointed; 

 the club 2-jointed; antennae of the male 12-jointed; anterior 

 wing with one marginal, one complete submarginal, and one dis- 

 coidal cell. 



Sp. 12. Myrmica fugax, Latr. 



Myrmica fiigax, Latr., St, Farg., Schenck, Smith, Mayr. 

 Myrmica Jlavidula, Nyland. Addit. Alt. p. S3. 



Worker, — Length 1 line. Worker : Pale yellow, smooth, shin- 

 ing and slightly pubescent ; the abdomen sometimes with a fuscous 

 band in the middle ; the mandibles 4-toothed ; tlie eyes minute ; 

 head very delicately punctured ; the thorax slightly constricted 

 behind ; the metathorax not spined. 



Female. — Length 3 lines. Nigro-fuscous, smooth, shining and 

 slightly pilose ; the mandibles, antennas and legs pale ferrvi- 

 ginous ; the head delicately punctured, with a deeply impressed 

 channel running from the anterior stemma to the apex of the 

 clypeus ; the clypeus with a tooth on each side of its anterior 

 margin. The first node of the petiole with a central depression 

 above. 



Male. — Length 2| lines. Black, shining and pilose ; the an- 

 tennae and legs fuscous ; the mandibles, articulations of the legs, 

 the mandibles and tarsi testaceous. 



This species is one of those which presents a great disparity in 

 the size of the sexes, the workers being the smallest, if we 

 except M. molesta, found in this country ; the difference in 

 colour is also remarkable, the male and female being nearly black 

 and the worker of a pale yellow. I first discovered workers of 

 this species at Southend, three years ago; this autumn I took the 

 female at Deal on the Sandhills. The male has not been taken 

 in this country to my knowledge. 



