ARMY ANTS IN BRITISH GUIANA. 293 



Although a number of male Ecitons were long ago described as 

 species of Labidus by Jurine (1807), Lepeletier (1838), Shuckard 

 (1840), Westwood (1842), Haldeman (1852), F. Smith (1859) and 

 Cresson (1872), the first to find a male in the nest with the workers 

 was Wilhelm Miiller (1886). He identified the species which he 

 studied at Blumenau, in the Province of Santa Catharina, Brazil, as 

 E. hamatum Fabr., but it proved to be burchclli Westwood. Mayr in 

 the same year described both the male and worker of E. (A.) hetschkoi, 

 taken by Hetschko from a nest in the Province of Parana, Brazil, and 

 Emery, in 1896, described the males of E. hamahun and quadriglume. 

 The former he seems to have determined by a process of exclusion, 

 the latter was taken from the nest by Schmalz's sons in the Province of 

 Santa Catharina. In 1900 Emery was able to recognize the males of 

 E. (A.) legionis and E. (L.) coecum. In the same year and in 1901 I 

 described the males of our North American E. {A.) schmitti Emery 

 and opacitliorax Emery. Forel described the male of E. (L.) prae- 

 dator Smith in 1906, and in 1912 I took the male of E. vagans Olivier 

 near San Jose, Costa Rica, accompan^dng a file of workers. Recently 

 Gallardo (1915) has found that the workers of the Argentinian E. (A.) 

 spegazzinii Emery are cospecific with the male previously described 

 as spinolcB hy Westwood, and Bruch (1916) has proved that the 

 worker E. {A.) nitens Mayr is cospecific with the same author's male 

 described as strobeli on a preceding page of his paper published in 

 1868. The male of E. (A.) pilosum Smith, described below, which 

 proves to be the same as mexicanwn Smith, and the male of E. (A.) 

 carolinense also described in this paper, complete the list of Ecitons 

 in which the males have been definitively correlated with cospecific 

 workers. Forel (1897) believes that his E. (A.) antillarum from 

 Grenada may be the worker of klugi Shuckard from that island and 

 St. Vincent, and it is very probable, as I have stated in a former paper 

 (1908, p. 410) that E. (L.) crassicorne Smith is the worker of esenbecki, 

 previously described by Westwood from a male specimen. I shall 

 also give reasons for regarding Labidus morosus Smith as the male of 

 Cheliomyrmex nortoni Mayr. 



Eciton burchelli Westwood. 



(Figs. 1-4, 5c, 6a-d.) 



Among the various Ecitons which I observed at Kartabo, this was 

 the most abundant and the most aggressive, and therefore the domi- 

 nant species throughout the jungle. Scarcely a day passed that I 



