100 bulletin: museum of compakative zoology. 



The promontory of which Cape Grafton (Plate XXXI.) is the ex- 

 tremity is interesting as heing a point which but slight additional 

 erosion would soon separate from the mainland. 



At the Hope Islands (Plate XXXII.) the reef may be said to have 

 encroached to the fullest extent upon the flats which surround these 

 islands ; they rise inside of the ten fathom line, and are not more than 

 two miles distant from the inner edge of one of the most interesting 

 reef patches (Cairns Reef) of this part of the Great Barrier Eeef. 



Both the Cairns and Endeavor reef flats rise from about fourteen 

 fathoms, and the distance from the inner edge of the reef patches to 

 the outer edge of the reef patches is about fifteen miles. The deeper 

 soundings close to the inside edge of the outer reef patches vary from 

 ten to twenty fathoms; the 100 fathom line is from two to three miles 

 from their outer edges. 



At the Hope Islands and extending to a point west of Cape Flattery 

 (Plate XXXIII.) begin a series of reef patches which have been more 

 carefully surveyed than those more to the south, so that at certain 

 stretches of this part of the coast our knowledge of the topography 

 of the reef flats and patches, extending the whole width of the reef, is 

 fairly complete. 



The only rocky islands within the ten fathom line are the Low and 

 Rocky Islets, and in addition we find within and outside the ten fathom 

 line a series of reef patches and reef flats which from their position and 

 condition we may fairly assume to be the remnants of former islands 

 once a part of the mainland and now covered on their surface mainly 

 with dead corals, while the slopes are covered with more or less flourish- 

 ing belts of coral extending to between the seven to ten fathom belt. These 

 reefs are, beginning at the Hope Islands (Plates XXXII. to XXXIV.), 

 successively lettered from Eh (a) Reef to En (n) Reef, a reef patch lying 

 to the north of the Turtle group. Some of the larger patches, such 

 as e Reef, Turtle Reef, Aitch (h) Reef, El (1) and Em (m) Reefs, and 

 Eagle Reef, all of which are well isolated reef patches rising from 

 twelve to fourteen fathoms in the channel between the inner edge of 

 the Great Barrier Reef and the mainland. These patches undoubtedly 

 represent the eroded flats of former islands, some of them of consider- 

 able size, which occupied the main part of the coast channel, much 

 as the group of the Lizard Islands, the Turtle group, and the Rocky and 

 Direction Islands now do. 



From the Hope Islands to off Cape Bedford (Plates XXXIL, XXX Hi.) 

 the width of the Barrier Reef patches varies from twelve to lifteen miles. 



