154 BRITISH ANTS. 



nest. They were not observed again for some time, but during the 

 winter of 1913 they were found to have excavated a small cell in 

 the earth in a corner of the nest, removed from their hosts. They 

 occasionally come out and walk about over the nest, and in the 

 wooden box which contains it, and sometimes visit a small hole in 

 a wooden support on the side of the box. When a Leptothorax 

 meets a Formica either sanguined, or fusca (slave) the former 

 stands still and the latter generally runs over it without noticing 

 it, but sometimes just tapping it with the antennae. This tiny 

 colony has lived peaceably in this nest for over nine months. 



On June 12th, 1911, I discovered a small colony of Leptothorax 

 acervorum situated under the bark of a log lying in a saw-pit, all 

 the ants of which were observed to be covered with a fungus, but 

 were quite active. The tube in which some of the ants were placed 

 was unfortunately lost, but the fungus was probably a species of 

 Laboulbeniaceae 61 . 



I have taken the Coleopteron Drusilla canaliculata F., in company 

 with L. acervorum at Fairlight 38 ; and Hallett has found the 

 crustacean Platyarthrus hoffmanseggi Brndt., with this ant at 

 Cwrt-yr-ala. 



The following forms of Leptothorax with twelve joints to the 

 antennae in the worker and female have been treated by some 

 authorities (Mayr, etc.) as good species, by others as races (Forel, 

 etc.) of L. tuberum, or subspecies (Crawley and Donisthorpe, etc.), 

 and again by others as varieties (Andre, etc.) of L. tuberum F. 



Without expressing any definite opinion on the subject, I prefer 

 here to treat them as species, as it certainly simplifies matters. 



The confusion which has arisen in Britain is chiefly due to the 

 fact that L. unifasciatus was supposed to occur in this country, 

 but nearly every British specimen recorded under this name must 

 be referred to L. tuberum F. 



Stenamma albipennis Curtis is not distinct from Leptothorax 

 tuberum F., though Dalla Torre erroneously gives it as a synonym 

 of L. nylanderi Forst. Curtis describes his albipennis as having 

 the club of the antennae in the worker fuscous, this proves that 

 his insect was not nylanderi Nylander sinks albipennis Curtis as a 

 synonym of unifasciatus Ltr., and F. Smith recorded L. unifasciatus 

 from Dover on the strength of specimens in Curtis' Collection 

 (these were obviously the Dover specimens described by Curtis as 

 albipennis). 



It is evident that both Curtis and F. Smith were aware that 

 considerable confusion existed with regard to the names of the 

 British species of this group, as the former wrote of L. tuberum 

 " This species requires investigation," and the latter writes 

 " The unifasciata of British collections is not that which continental 

 Hymenopterists consider to be Latreille's species ; in one respect 

 it does not quite agree : the female has, in fact, three bands on the 



