LEPTOTHORAX. 159 



I found specimens occupying the burrows of a beetle, Priobium 

 castaneum, in a broken bough on an old ash at Ryde, Isle of Wight 26 

 on October 23rd, 1908, and Baynes discovered a small colony 

 tenanting an old disused burrow of the " Clear -Wing," Sesia 

 andrenaeformis, in a twig of Viburnum lantana near Cookham in 

 Buckinghamshire on June 28th, 191 1 27 . 



Leptothorax nylanderi has also occurred in the nests of other ants 

 F. Smith wrote in 1868 : " The Leptothorax nylanderi has never 

 been found in any other situation than in ants' nests, usually 

 those of Formica rufa." 9 He does not give any references, I am 

 not aware of any records of this ant being found in rufa nests, and 

 I think he must have had some other species, probably Formicoxenus 

 nitidulus, in his mind. 



There are, however, records of the occurrence of L. nylanderi 

 with species other than F. rufa Rothney captured a few specimens 

 in a nest of F. sanguinea at Shirley, in 1867 17 , and in his collection, 

 now at Oxford, there are specimens taken with Donisthorpea fuli- 

 ginosa at South Norwood, and by Dr. Power with the same ant at 

 Claygate on May 12th, 1867. 



Saunders found it on Whit Monday, 1883, in company with 

 D. fuliginosa on a bank at Chobham 18 , I took both dealated 

 females and workers in a nest of the same ant at Oxshott 24 in March, 

 April, and May, 1896 and 1897, workers at Wellington College 25 in 

 April and May, 1906, and on September 7th, 1913, a dealated 

 female in a nest of D. mixta in a tree root at Box Hill 29 . 



According to Mayr, L. nylanderi swarms in midsummer 5 , 

 Schenck took the winged forms in the nest on August 21st, and in 

 grass on September 25th and October 15th at Nassau 3 , and Forel 

 found males in abundance in nests at Vaux in September, 1867 12 . 

 Champion caught winged females by sweeping at Esher on 

 September 20th, 1874, and Morley obtained all three castes beneath 

 poplar bark at Tattingstone in October, 1899 23 . On October 10th, 

 1914, 1 found two males in a colony under poplar bark near Ipswich. 



Forel kept a colony of this species in captivity in April, 1868, 

 which consisted of a dealated female and sixty workers, and many 

 larvae were brought up from the queen's eggs, but he found they 

 would not rear strange larvae. The workers would sometimes 

 devour insects given to them, and males and workers were produced, 

 the former appearing on June 29th and during July 11 . 



On October 9th and 10th, 1912, I found two colonies of Lepto- 

 thorax at Yvorne, Switzerland, each being situated in a hollow 

 walnut stick, the one being L, affinis, the other L. nylanderi. I 

 brought both sticks home and introduced their contents into a 

 four-chambered " Janet " nest. Each colony consisted of a 

 dealated female, workers, and larvae, but males were also present 

 in the stick belonging to the affinis. The two species joined forces, 

 without any fighting, all the larvae were collected into one heap 



