106 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
the ship “ Wansfell Іп 1864 she passed into the reef through an 
unknown opening about latitude 20? 30' S., and came out opposite 
Port Denison. 
As we proceed northward, corals become more and more abundant, 
skirting parts of the islands from which too great quantities of detritus 
are not washed down in the rainy season, or wherever a locality presents 
itself, favorably placed as regards the food supply or the purity and 
depth of the water. 
On our way north from Keppel Bay we could only examine the 
numerous islands we passed in the most superficial manner. The state 
of the sea prevented us from landing either at any of the Northum- 
berland Islands, or the Percy Islands, or the southern group of the 
Cumberland Islands. It was only when we reached the southern 
extremity of Whitsunday Passage (Plate XXX.) that we were able to 
examine the small reefs which skirt part of the shores of the greator 
number of the larger islands forming the eastern belt of the passage. 
The bank in Cid Harbor (Whitsunday Island) to the north of our 
anchorage, which slopes gradually from the shore to two or three 
fathoms, was covered by fine masses of coral. They apparently did 
not stretch into deep water, for near our anchorage, which was in only 
six fathoms, there were no corals, the bottom being mud and broken 
shells, Тһе corals formed a belt (a kind of plateau) of a certain width 
on the slope. The Astraans were marked for their size. Huge masses 
of whitish Aleyonaria were very active, the long-stemmed individuals 
of the colony twisting and bending in all directions. The abundance 
of soft masses of Aleyonaria seems to be a characteristic of the coral 
reefs of Australia, where they replace the Gorgonians of the West 
Indian reefs. The masses of Astroans, of Mecandrinas, and of Porites 
were also uniformly larger than we find them on the West Indian coral 
reefs. Between the heads were buried Tridacnas of varying sizes, and 
sponges were also far more common than is the case in the West 
Indian reefs. 
At Langford Island (Plate XVIIL), a small island at the northern 
extremity of Whitsunday Passage, we examined the coral recf which 
extends for about a mile to the south and east of tho island. The two 
extremities of Langford Island are connected by a sandbar, and on the 
slopes of the recf flat, which is bare at low water, corals flourish in 
froin two to three fathoms. At the southern extremity of the reef flat 
are two low islands, the remnants of the spit which once connected 
them with the higher island at the other end of the reef flat. The 
