434 R. H. CAMBAGE. 



flood-line. At the bead of the Flinders, near Hughenden, 

 Ooolabah trees were seen with box bark on the trunk and 

 lower portion of the large branches, the remainder being 

 smooth, and having fruits with exserted valves. Similar 

 trees were noticed between Hughenden and Winton, and 

 are common around Longreach, and eastwards intermit- 

 tently to Rockhampton, some of the young trees at Long- 

 reach having the upper portion of the trunk white, as well 

 as the branches. Briefly then, it would seem that the 

 Bourke form of E. microtheca with the upper portion of 

 the tree smooth, and having fruits with exserted valves, 

 extends northerly to the upper Flinders with some variation 

 in the extent of box bark on the trunk, while near the Gulf 

 of Carpentaria the whole tree is covered with box bark and 

 the fruits have scarcely exserted valves. These differences, 

 although meriting further investigation as being possible 

 adaptations to environment, cannot in themselves be con- 

 sidered specific. 1 



Eucalyptus pallidifolia is an interesting species which 

 was seen at various points on the slightly elevated 

 Cretaceous sandy or gravelly areas, avoiding all basic 

 formations. It was first met with about fifteen miles north 

 of Donor's Hill, and was last seen near Cloncurry on what 

 appears to be Silurian slate. Its local names are Mountain 

 Gum, or White Brittle Gum, and in general appearance it 

 resembles a spreading stunted form of E. maculosa R. T. 

 Baker, its average height being about thirty feet. (Plate 

 LVIII, fig. 1). The type came from North Western Aus- 

 tralia, and Mr. Ross McLean of Bowen informed me that 

 this species was very common towards the western border 

 of North Queensland, but was rare east of the Flinders. 

 The timber is hard, short grained, and red, the sapwood 



1 See " A Critical Revision of the Genus Eucalyptus/' by J. H. Maiden, 

 Part xi. 



