ARMY ANTS IN BRITISH GUIANA. 311 



also constructs galleries or cause-ways of particles of soil. When 

 foraging or migrating its columns are conspicuously broader and 

 denser than those of other army ants. Bates (1863) and Mann (1916) 

 have described its habits in Brazil. The latter, who observed it along 

 the Upper Madeira, says: " Houses along the railroad were frequently 

 raided at night by E. pracdator, which is well-known to the Brazilians 

 and called by them "cazadoro" (hunter). I had the opportunity of 

 observing one hut while the ants were in possession. The ground was 

 covered with the ants, which swarmed also in the cracks and on the 

 few pieces of furniture, while the owner of the place, a Barbados 

 negress, not accustomed to such intrusions, stood for safety in a puddle 

 of soapy water with which she had attempted to drive the ants away, 

 and begged me to tell her what to do to get rid of them." 



E. praedaior is not common at Kartabo, and the few foraging col- 

 onies I encountered were much smaller than those described by Bates 

 and Mann. INIoreover, they belonged to an undescribed variety 

 which I shall call guianense var. nov. The soldier of this form is 

 smaller than the type and measures only 7.5-8.5 mm. ; head 3-3.5 mm. 

 (typical form 8.5-11.5 mm.). The upper surface of the head is de- 

 cidedly more opaque, very finely, densely and evenly pimctate or 

 reticulate, with the larger, sparser, piligerous punctures more indis- 

 tinct. The body is paler, being dull ferruginous, with pale brown 

 legs and blackish gaster. The worker, however, is darker and colored 

 more like the typical form, but the head is somewhat less shining 

 above. Though considerably darker, guianense approaches the sub- 

 species em'diw Mann in color, but is much closer to the type. In the 

 soldier emilicc the head is more finely and more indistinctly sculptured 

 and somewhat glossy and the gaster and sides of the thorax are less 

 shining. The var. ferruginea Norton from Mexico is probably closely 

 allied to guianense but was inadequately described. Santschi has 

 based a subsp. auropuhens on male specimens from French Guiana 

 and this may prove to be covarietal with my soldiers and workers from 

 Kartabo. In my collection there are a few soldiers and workers taken 

 by Forel at Esperanza, Colombia, which also belong to the var. 

 guianense. 



Eciton (Acamatus) angustinode Emery subsp. 

 emersoni subsp. nov. 



This small form, which I dedicate to Mr. Alfred Emerson, was seen 

 only on two occasions at Kartabo, once rapidly running over the logs 

 of an old stelling and once migrating with larva? across the sandy soil 



