BY G. F. HILL. 145 



Head very large, longer than wide, widest at the insertion of the antennae, 

 with very few setae. Labrum large, convex, narrow at the base, wide on the 

 sides and rounded in front. Postclypeus large, convex, twice as wide as long, 

 a dark brown spot at either end; anteclypeus hyaline with yellow suffusion on 

 either side of the middle line, anterior margin produced in the middle. Antennae 

 (Text-fig. 8) 15-jointed, joints long and slender, second shorter than third, fourth 

 longer than third. Maxillae as in Text-fig. 9. 



Pronotum similar to that of soldier; margin with a few long stout setae. 



Legs long and slender, with scattered reddish setae. 



Abdomen large, widest in the middle, clothed with scattered long and short 

 setae; cerci short and stout. 



Measurements : 



Total length 6.00 mm. 



Head: long 2.00; wide 1.73. 



Thorax and abdomen, long 4.00. 



Antennae (15-jointed) 2.35. 



Pronotum: long 0.47; wide 0.90. 



Tibia iii. 1.75." 



Abdomen, wide 1.70. 



Affinities. — The imago is distinguished from E. palmerstoni, to which it is 

 evidently closely related, by its much larger eyes and ocelli, proximity of the 

 latter to the former, differently shaped antennae, shorter abdominal tergites (the 

 third segment being 0.61 as against 0.71 in palmerstoni), markedly emarginate 

 posterior border to meso- and metanotum (much straighter in palmerstoni) , and 

 less deeply emarginate posterior border to pronotum. The soldier appears to be 

 nearest E. nigerrimus var. queenslandicus Mjob. (Text-fig. 10 and 11) and E. 

 magnu-s Frogg. From the former (alate form not known) it differs chiefly in 

 having smaller and less rounded head, longer and more slender snout and 

 straighter dorsal surface in profile. These differences are slight, but they are at 

 least as well marked as those which separate soldiers of certain allied species 

 which are very distinct in the alate form. The tei-mitaria of these two are so 

 dissimilar that it is not at all likely that they are constructed by individuals of 

 the same species. I have not had authentic examples of E. magnus Frogg. for 

 examination, but from the description of the soldiers and Dr. Mjoberg's remarks 

 upon them, they are evidently very similar to E. vernoni. The termitaria, too, 

 are evidently very much alike, but the difference in the alate forms is very 

 marked indeed. 



Biology. 



The termitarium. and its occupants. — The termitaria are to be found in im- 

 mense numbers on the low treeless or nearly treeless country in the vicinity of 

 Townsville' (PI. xxiv. fig. 1), where they are associated with the mounds of two 

 other very common species, Hamitermes wilsoni Hill (H. perplexus Hill) and 

 Drepanolermes silvestrii Hill. In shape they are more or less rounded 

 circular at the base and sloping on the sides to the broadly rounded or 

 apex. The sides are often symmetrical, but generally undulating as a result of 

 accretions made from time to time to meet the needs of the increasing colony. 

 The average dimensions of these termitaria are about 2 ft. 6 inches in diameter 

 at the base by 2 feet in height, but they are sometimes more than twice this size. 

 The walls are composed entirely of heavy loamy soil, moulded into a close- 

 textured mass free from the short lengths of grass found in the structures of 



