142 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
gradual pitch in the continental slope, and there is nothing to indicate 
that the outer Barrier Reef patches rise from very great (4 unfathom- 
able") depths. On the contrary, the outer reef patches are all well 
within the 100 fathom line, and at a distance from it, except, whero tho 
pitch of the continental slope is unusually steep. The inner reef patches 
all come up from a line which cannot be of greater depth than about 
twenty fathoms, that being the average depth of tho first inner chan- 
nel between the outer patches of the Barrier Reef and the outer line of 
inner reef flats. The inner line of reef flats rises from a lesser depth, 
not more than ten to fifteen fathoms. The section lines passing from 
the mainland to the line of outer barrier reef, across high rocky islands 
and reef flats, indicates that the coral reef rock and coral reefs can only 
constitute a comparatively thin sheet from the outer line of inner reef 
flats towards the mainland, and that this sheet probably does not extond 
beyond the lower slope of the islands which they surround, and the 
base of which is formed by the submarine extension eastward of the 
strata of the continental slopes. Апа furthermore that the outer barrier 
reef probably does not rise from a much greater depth than that at 
which reef-building corals can flourish. 
Kent has followed very much the same line of argument as Jukos, in 
assigning the formation of the Great Barrier Reef to the depression (in 
recent times) of the northern part of the Australian continent, — a do- 
pression, however, which must have taken place during cretaccous times. 
But he lays no stress on the connection which must have existed in 
comparatively recent times between Australia and New Guinea, during 
the early part of the formation of the Great Barrier Reef, — a connection 
fully recognized by Jukes," who seems to have been most successful in 
applying the principles of Edward Forbes in the distribution of the 
British Fauna and Flora to those of Australia and New Guinea. 
It is interesting to note that Jukes, while convinced that the northeast 
1 Voyage of the “ Fly," Vol. I. p. 347. Jukes writes: “It follows that, during 
the early part of the period of their formation, Torres Strait, and the shoal seas on 
each side of it, were dry land, and Australia connected to New Guinea. This would 
explain, perhaps, the fact of the marsupial type of animals being common to both, 
though the genera and species are different. It would explain also the difference 
in the assemblage of shells, ete., on the northern and southern sides of 'lorres 
Strait mentioned before, page 229, as each group would spread into the newly 
formed sea from the nearest adjacent shores, the Molucca group coming from the 
north, and the Australian from the south. The existing vegetation of the two 
countries would seem to have originated, or at least to have spread over their 
opposite shores since their separation." 
