BY D. MAWSON. 411 



a peak 1000 ft. in height. A dolerite collected from this island 

 has been described by Mr. J. J. H. Teall. 



Mai lies four miles N.E. of Makura, and has approximately 

 the following dimensions : length 5J miles, breadth 2^ miles, and 

 an area of 7 J sq. miles. Capt. Cook named it Three Hills Island 

 on account of a well marked topographical feature; the highest 

 of the peaks reaches an elevation of 2171 ft. Lieut. Frederick 

 has reported the island to be of volcanic origin. 



The Cook Reef is an example of a coral atoll in its earlier 

 stages of development. As we were not able to visit this interest- 

 ing spot, we can only quote from the Admiralty surveys. Its 

 external dimensions are roughly 2 miles by 1 J miles. The lagoon 

 is completely enclosed by a belt of growing coral reefs which are 

 exposed at low tide in patches for a width averaging about a 

 quarter of a mile. The absence of permanently dry land is no 

 doubt owing to its youth, and it is probable that in a compara- 

 tively short time to come patches of land will make their appear- 

 ance, due to the piling up of broken off fragments of reef-material. 

 The future histor}'- of the atoll is entirely dependent on local 

 movements of the earth's crust, in so far as if the upheaval, so 

 generally evidenced throughout the Group, be continued, the Cook 

 reef will some day be presented to us as another Mango; if, on 

 the other hand, a slow subsidence makes its appearance in the 

 Group, then by upgrowth and outgrowth a typical coral atoll of 

 the Funafuti type might result. 



The Shepherd Islands are a group of seven small islands, 

 together with numerous islets, reefs and banks, extending S.E. of 

 Epi for a distance of 14 miles. Lieutenant Frederick describes 

 the Shepherd Islands as being all of recent volcanic origin. He is 

 of opinion that they once formed part of a huge crater. As sub- 

 stantiating this argument, he refers to a native legend to the 

 effect that about 300 years ago the land broke up in this vicinity 

 and remnants only were left, forming the present system of 

 isolated islands. However far this may be true, there certainly 



