THE yOUNG NATURALIST. 



271 



BRITISH ANTS— By G. C. BIGNELL. 



(Continued from page 255 J 

 Genus LEPTOTHORAX, Mayr. 

 The female and worker in this genus present 

 the peculiarity of having their hairs clavate, 

 — a character easily seen with a strong lens. 



1. Leptothorax acervorum, Fab 



Male.— Black ; mandibles and legs brown, 

 joints and tarsi paler ; clothed with long 

 whitish hairs, especially on the dull, rugose 

 head ; mandibles not toothed ; antennae 

 twelve-jointed, scape very short and thick, 

 about as long as the second joint of the 

 flagellum, which is much longer than the 

 first ; metathorax tuberculated at the sides 

 behind ; nodes of the petiole smooth and 

 shining ; abdomen shining and smooth ; 

 wings white. Length, 5 mill. 



Female.— Brownish red ; head, thorax, 

 and abdomen above, nearly black ; mandi- 

 bles, scape and legs, paler ; antennae eleven- 

 jointed ; head finely and longitudinally 

 rugose ; thorax and nodes of the petiole 

 also rugose ; metathorax with two stout, 

 rather blunt spines ; abdomen shining, with 

 scattered white hairs ; legs with prominent 

 hairs. Length, 4-5 mill. 



Worker. — Testaceous, red ; head, apex of 

 antenna;, and abdomen nearly black ; thorax 

 sometimes with a more or less extended 

 dark patch on the disc ; entire insect clothed 

 with scattered short, upright, pale hairs ; 

 head and thorax rugose ; antenna; twelve- 

 jointed ; metathorax with two short, rather 

 blunt spines ; first node of the petiole nearly 

 quadrangular, looked at from above, — from 

 a side view much raised posteriorly ; both 

 nodes more or less rugose ; abdomen smooth 

 and shining. Length, 4 mill. 



Habitat. — Often found under bark of 

 old trees, &c., chiefly in the north. It has 

 been taken in the London district; also at 

 Dawlish and Woolcacombe, in Devonshire. 



2. Leptothorax Nylanderi, Foerst. 



Male. — Brown ; the mandibles, antenna:, 



and legs pale ; mandibles four or five- 

 toothed ; scape of the antenna; as long as 

 the first three or four joints of the flagellum ; 

 the first seven joints of the flagellum are of 

 about equal lengths, the following four are 

 thicker and longer, and the apical joint is 

 almost longer than the two preceding to- 

 gether ; thorax in front of the converging 

 lines smooth and shining, behind finely and 

 longitudinally rugose ; metathorax finely 

 rugose, and with two small tubercles ; abdo- 

 men shining, the nodes of the petiole smooth 

 above. Length, 2 mill. 



Female. — Testaceous, club of the anten- 

 nae of the same colour ; abdomen black- 

 brown, with the base of the first segment 

 widely, and the following more or less nar- 

 rowly, testaceous ; head and thorax longitu- 

 dinally striate, clothed with scattered club- 

 shaped hairs ; thorax as wide as the head ; 

 wings slightly milky, nervures very pale ; 

 metathorax with two sharp spines, very wide 

 at the base ; abdomen shining, clothed with 

 scattered hairs. Length, 5 mill. 



Worker. — Differs from the female only 

 in having the thorax much narrower than 

 the head and constricted in the middle, its 

 surface rather more rugosely striate, and 

 the spines of the metathorax rather longer, 

 and in being smaller in size. Length, 2 mill. 



Habitat. — Not common ; has been taken 

 at Chobham, Wimbledon, and Exeter. 



3. Leptothorax unifasciata, Ltr. 



Very like the preceding. Messrs. Forel 

 and Emery consider it a race, uniting them 

 under the name oiiuberum, Nyl. 



Male. — May be known from the preced- 

 ing by having the thorax in front of the con- 

 verging lines rugose. 



Female. — ^L1y be known by having the 

 apex of the antennae dark brown, and the 

 black bands of the body narrower, often 

 wanting, except on the basal segment. 



Worker. — Like the female. 



{To be continued on fage 2S7.) 



