MR. G. BEKTIIAM ON MTETACE.E. 151 



the first monotypic, the second of very few species, connecting, as 

 it were, Psidium with Myrtus, but retained in order the better to 

 draw the line between those large genera. Both have usually the 

 4- or 5-celled ovary and the ovules of Psidium, but the bud is 

 crowned with large leafy calyx-lobes; in Psidiopsis the calyx-limb 

 splits below these lobes as in Psidium ; in Calycolpus it is either 

 not developed below the lobes or is very short and expands with- 

 out splitting as in Myrtus ; and in one species, C. calopliyllus. 

 Berg, these lobes are scarcely foliaceous. The embryo is unknown 

 in Psidiopsis ; in Calycolpus it is like that of Psidivm and Myrtus, 

 The habit of both is nearly that of Psidium^ although in Calycolpus 

 it may sometimes be thought to come nearer to that of the section 

 TJgni of Myrtus, 



Rhodomxrtus, DC, was originally proposed, as either a section 

 of Myrtus or a distinct genus, for the pink-flowered M. tomen- 

 tosa, remarkable for its triplinerved leaves like those of Malasto- 

 maceae. This, however, which was believed to be the principal 

 character, was ultimately not thought by DeCandoUe to be of 

 higher than sectional value, notwithstanding some differences 

 observed in the arrangement of the ovules and the supposed 

 increased number of cells. But the recent addition of four Aus- 

 tralian species, and a careful study of the ovary and fruit, have 

 since pointed out other characters which, together with the 

 habit, nearer to that of Psidium than of Myrtus, have induced us 

 to adopt Mhodomyrtus as a genus. The venation of the leaves 

 has not proved constant ; for of the five species two only are 

 triplinerved, one is penninerved, and the remaining two show an 

 intramarginal vein, more or less incomplete or perfect, so as to 

 form the passage from the one to the other. The ovary is, as in 

 Myrtus, 2- or 3-carpellary, or in one species reduced to a single 

 carpel ; but the ovules are superposed in two long rows in each 

 carpel, with a longitudiual spurious septum between the rows, so 

 as, on a transverse section, to give the appearance of twice as 

 many cells as carpels ; besides which, spurious transverse septa, 

 like those of Timonius (or Nelitris, Grsertn.) in Eubiacese, sepa- 

 rate each seed — a circumstance not hitherto observed in any other 

 Myrtacea, its having been indicated in Decaspermum (Nelitris, 

 Lindl.) being, as I shall presently have to point out, erroneous. 



The typical genus Myrtus is the one to which it is perhaps 

 the most diffictdt to assign its proper limits. Originally dis- 

 tinguished from Etiyenia by the fruit, evidently 2- or 3-celled, 

 instead of apparently 1-celled (the structure of the ovary being 



