330 J. H. MAIDEN. 



Some species possess a double operculum or membraneous 

 bract enveloping the whole of the young inflorescence. It 

 was first observed by Robert Brown (see his description of 

 Euclesmia tetragona), but a few years ago it was only 

 recorded from a very few species. In some it is very early 

 deciduous and, in others infrequent, but I have observed it 

 in such a large number of species that I am inclined to the 

 opinion that extended research will show that it occurs in 

 all. Brown's and Jussieu's interesting observations on the 

 single and double operculum will be found supplementary to 

 the former's description of Eudesmla tetragona (Bot. App. 

 to Flinders' Voyage). 



Anther — Bentham (Flora Australiensis) first grouped 

 species according to the shape and mode of dehiscence of 

 the anthers. He made five groups, but laid no stress on 

 the importance of the dehiscence of the top on the anther. 

 He however, alludes (B. Fl. iii. 186) to "truncate" anthers, 

 and at page 189 to the truncate anthers of E. leucoxylon. 

 Mueller, finding that Bentham's five groups could not be 

 separately maintained, reduced them to three, viz : — 



(a) Renantherce, the anthers large and the cells diver- 

 gent at the base. 



This section mostly includes the Stringybarks, although 

 it includes several White Gums, plants otherwise very 

 different. 



(b) Porantherce, the anthers small an opening in pores. 

 This section mostly includes Boxes and some Mallees, 



and includes the Silver-leaved Ironbark (melanophloia), 

 while E. crebra which is very closely allied to it is placed 

 in another section. 



(c) Parallelantherce, the cells parallel, and the longi- 

 tudinal slits consequently parallel. 



This section comprises the remainder of the Eucalypts, 

 and a most heterogeneous and extensive collection they 



