148 



tionally higt from tlie overwlielming number o£ Dicotyledons 

 in West Australia. The ratio of tlie two classes in that flora 

 is 1 to 5 '3, and that for Kangaroo Island comes nearer to it 

 than any provincial flora. This high ratio is the more remark- 

 able when examined from a geographical point of view. It 

 contrasts most markedly with that of Tasmania, with which it 

 has many specific points of contact, the ratio for Tasmania 

 being 1 to 26 ; whilst South Australia, which claims 97 per 

 cent, of its species, the ratio is 1 to 3'7. 



The sequence of the ordinal groups, according to predomi- 

 nance of their numbers of species, is as follows : — Compositae, 

 43; Myrtaceae, 33 ; Leguminosae, 27 ; Cyperaceae, 24 ; G-ramineae, 

 20; Umbelliferae, 14; Epacrideae, 11; Proteaceae, 11. These 

 orders are also the first seven in a like arrangement for the 

 Australian flora, though their relative positions are not the 

 same. In the South Australian flora, Proteacaa and Epacrideae 

 give place to Salsolaceaa and Orchideae; and in Tasmania, 

 Orchideae and Eilices replace Myrtaceae and Proteaceae ; but in 

 West Australia the similarity is greater, inasmuch as Gramineae 

 occupies the eighth place, being deposed from the seventh 

 by Goodenovieae, and Myrtaceae stands second, the same posi- 

 tion it occupies in the Australian list and in that of Kangaroo 

 Island. 



The remarkable morphological diversity is indicated by the 

 presence of 230 genera, belonging to 69 orders ; so that the 

 ratio of genera to species is 1 to I'S ; whereas for the Austra- 

 lian flora it is 1 to 6'4 nearly, and for South Australia 1 to 3*6, 

 and for Tasmania 1 to 2'6, the lowest among the provincial 

 floras. 



The genera containing more than three species to each are : — 

 Eucalyptus, 14 ; Acacia and Styphelia, 11 ; Pimelea, 9 ; Mela- 

 leuca and Hydrocotyle, 7 ; Cryptandra and Scirpus, 6 ; Aster, 

 Helichrysum, Schoenus, 5 ; Hibbertia, Lasiopetalum, Drosera, 

 Triglochin and Leptospermum, 4. 



Conclusions bespectin& Eelationship of the Floea. 



1. The small number of peculiar species does not entitle 

 Kangaroo Island to the rank of a botanical region. 



2. The large proportion of its species being common to the 

 mid-southern districts of South Australia, Kangaroo Island 

 becomes a part of that botanical region. 



3. The number of its peculiar species and those of Tas- 

 manian origin entitle it to a subregional rank. 



4. The absence of a large number of species, alien and en- 

 demic, widely spread over the continent would seem to imply 

 isolation before immigration of the extra-Australian species 

 and those endemic ones of marked exotic genera to the shores 



