52 Zoologica: N. Y. Zoological Society [HI; 3 



compactly jointed and distinctly clubbed at the tip. The female 

 is, perhaps, somewhat smaller than the male, but I have been 

 unable to detect any other external differences between the sexes, 

 and Schwarz and Barber in their more careful study of the struc- 

 tural peculiarities of the species, have been no more successful. 

 For further details the reader is referred to their taxonomic 

 description in Zoologica III, No. 6. 



The eggs (Fig. 11) are pure white, regularly elliptical, 0.55 

 long and 0.25 mm. broad, with rather thick, leathery, smooth 

 and shining chorion. The larva is described and figured in great 

 detail in Dr. Boving's article (Zoologica III, No. 7, Plates VII 

 and VIII) . In life it is whitish and beautifully translucent so that 

 the straight alimentary tract and its contents can be distinctly 

 seen, but as maturity approaches the body becomes more opaque 

 and milk-white, owing to a considerable increase in the fat-body. 

 The pupa is even more opaque, but just before eclosion becomes 

 yellowish or testaceous, with pigmented eyes. Both beetle and 

 larva are very active and alert, the latter at all times, the former 

 when hungry or disturbed. At other times the beetle is rather 

 sluggish or quiescent, but shows no tendency to "feign death" 

 when handled. Though its wings are well-developed (Plate VI, 

 fig. 5) I have never seen it attempt to fly. The pupa (Plate 

 IX, figs. 19-21) is also very active when stimulated, wriggling 

 its abdomen from side to side, but is unable to move about. 



The beetles enter petioles which have either not been pre- 

 viously perforated by other insects or those which have been 

 occupied for some time and have then been abandoned by ants 

 or other beetles or have been occupied by queens of Pseudoniyrma 

 or Azteca that have died before they could produce their broods 

 of workers. The beetles either enter as a single pair or one 

 beetle enters and is very soon joined by an individual of the 

 opposite sex. I have been unable to decide which of these 

 methods is followed or whether the opening in the petiole is 

 made by the male or the female or by either indifferently. Cer- 

 tainly the great majority of colonies in their first, or incipient 

 stage consist only of a male and a female beetle. On the rare 

 occasions when only a single beetle was found in a petiole, the 

 other may have escaped or eluded my attention while I was 

 cutting into the cavity. Twice I have actually seen both beetles 



