Fun, ml Subvegions of Australia. 145 



(2) Middle Torresian District. — This extends from about the 

 bottom of the Gulf of Carpentaria to near the tropic, having the 

 Bellenden Kerr Mountains for its central feature. The genera 

 Steganomma (tribe Scaritini), Mecynognathus and Loxogenius (tribe 

 Pterostichini) arc not found beyond the limits of this region; also 

 Rhysopleura, a remarkable genus of the family Cicindelidae. 



(3) South Torresian District. — This extends from the tropic to 

 the Clarence River. Its typical Carabidae are found from the Bur- 

 nett to the Richmond River. Liopasa, Leirodira and Notolestus 

 are distinctive genera (tribe Pterostichini) belonging to this district. 



The Bassian sub-region is a country of mountains, rivers and 

 forests. In its past history we may imagine great ranges of moun- 

 tains covered with perpetual snow, which presented a barrier to 

 the southward progress of the fauna of the north; for this reason, 

 we may suppose the Cicindelidae failed to reach Tasmania, or, 

 except as very recent immigrants, Victoria south of the dividing 

 Range; for the same reason such characteristic Australian groups 

 of the Carabidae as the Carenums and Helluonini have not extended 

 to Tasmania, and are hardly represented in Southern Victoria. 



Through the continental part of the Bassian sub-region five 

 reciprocal routes of past migration may be perceived; viz., three 

 from north to south, and two from east to west. The north and south 

 routes will be, one over and along the mountains, and a route on each 

 side of the mountains available for the fauna of the lowlands. Such 

 species as the Carenums Laccoscaphus loculosus and L. fovei- 

 pennis may be taken as lowland forms, which spread into Victoria 

 and the south-eastern parts of South Australia along the western 

 lowland route. The two east and west routes will be, (a) Tate's 

 Post-Miocene route across a former southward extension of Aus- 

 tralia. This must have been a forest-clad land across which have 

 passed, such Carabidae as the ancestors of the present species belong- 

 ing to the genera Promecoderus, Amblytelus, Platylytrori, Hor- 

 macrus, and the single species of Notonomus found in Western 

 Australia, (b) The route which became available on the union of 

 the Bassian and Eyrean sub-regions, and which has been taken 

 advantage of by both Bassian and Eyrean types. 



In the scheme proposed by me the Bassian sub-region was divided 

 like the Torresian into three districts, viz.. a northern, middle and 

 Tasmania. There is apparently no true line of demarcation between 

 (4) the North Bassian district, which centres on Sydney, and (5) the 

 Middle Bassian district, of which the Australian Alps are the great 

 natural feature. 



