FAUNA OF THE MONTE BELLO ISLANDS. 627 
The Monte Bello rock is comparatively poor in Foraminifera, 
but contains numerous fragments of broken shell. Most of the 
lime is concentrated near the surface, and the bare hill-tops on 
Hermite Island are covered in places with an extremely dense 
and hard marble-like surface deposit, only a few inches in thick- 
ness, formed by rapid surface-evaporation drawing up the water 
from the lower levels and depositing its mineral contents. 
The main geographical features of the group are indicated on 
any map. It lies at the northern extremity of an extensive 
shoal, which stretches in a southerly direction to within fifteen 
miles of the mouth of the Robe River, including Barrow, a com- 
paratively large island lying twelve miles S. by S.W. of the 
Monte Bello Group. The southern portion of this shallow area, 
known as Barrow Island Shoals, has soundings of 23 fathoms, 
and dries in patches at low water. This closely approaches 
another bank, which lies between the mouths of the Cane and 
Robe rivers, including the Mary Anne Islands. The passage 
between these shoals is only four miles wide, and nowhere more 
than nine fathoms in depth. Half encircling the Monte Bello 
Group on the north and west sides is Breakin’s Reef, which is the 
actual limit of the bank. It is nota coral formation, although 
there are plenty of corals upon it, and it dries in patches at low 
water with the spring tides. Outside the ‘reef? soundings of 
40-50 fathoms are struck almost immediately. It seems likely 
that this shallow area at one time formed an extensive triangular 
cape, of which the Monte Bello Islands formed the northern 
extremity, having become separated at a comparatively recent 
period. Barrow Island was probably connected with the Monte 
Bello Islands long after its separation from the mainland, a 
supposition supported by zoological evidence hereafter to be 
dealt with. 
It will be weil now to describe the respective characters of the 
two main islands, Hermite and Trimouille. 
Hermite Island, the largest and most fertile, measures rather 
over six miles from N. to S., and about one and three-quarters 
across at its widest part. The coast-line is irregular, and ex- 
tensive shallow inlets run far inland amongst low undulating 
hills, nearly dividing the island longitudinally into an Eastern 
anda Western portion. The coasts facing the open sea are rocky 
and irregular, with low rugged cliffs and stony beaches; but 
the shores of the inlets are regular and characteristic, the hills 
sloping down to a flat rocky terrace, which is bare of vegetation 
and washed by the sea at very high tides in windy weather. 
This terrace descends nearly perpendicularly to the regular tidal 
flat, and its edge is much undercut, owing to the tides which flow 
swiftly up and down the long and narrow inlets, and to the 
absenee of big seas, which would break up the configuration. 
Since these inlets are locally called ‘lagoons,’ I shall continue to 
speak of them as such, though they have nothing to do with the 
true lagoons associated with coral formations. In the sheltered 
