Considering the extent of interior known, at the present 
day, in or about the parallel of Port Jackson, as also oil the 
north and south of that degree of latitude, the terrestrial part 
of the family may be said to he comparatively rare in the 
inland country. In their journeys through it at various sea- 
sons, botanic travellers have observed hut thirteen species; 
and the whole of them are of genera, and indeed for the greater 
part, of species, frequent on the sea coast at or near Sidney. 
These genera are Diuris, Orthoceras, Calochilus, Cala- 
denia, Lyperanthus, Pterostylis, Gastrodia and Dipodium. 
In fine, as a general remark on the geographical range of the 
family in Australia, it may be observed, that as the terrestrial 
species are greatly influenced by rains that may fall in the 
season when they would under such favourable circumstances 
appear above the soil, and as those whose localities are in- 
land, beyond the range of those genial coast-showers which 
occasionally fall in the midst of a long period of drv weather, 
are wholly prevented from appearing above ground for two 
or three years, to which extent the droughts in that country 
have continued; these facts are sufficient to explain why it is 
that this group also of the order in Australia, is so much 
more abundant on its immediate shores, than it is either in 
the up-country, as those parts of the colony a little distant 
from the coast are termed, or the more remote interior. 
exceedingly thinly and generally lightly wooded, and thus its ample surface 
being greatly exposed to the rays of the sun, an extreme dryness of atmosphere 
is engendered, by no means favourable to the existence of a shade-loving 
vegetation, affecting a lower temperature, but cooled simply by the surround- 
ing air being, to a certain degree, permanently charged with humidity. 
