DEPARTMENT OF MARINE BIOLOGY. 187 



sea-cliffs now seen around the islands of American Samoa were cut. 

 Finally the sea sank to its present level, and then a new set of reefs 

 began to grow outward from the shores to form the present fringing 

 reef of Tutuila. \Miere the submarine slopes are gradual, as at the 

 inner ends of the drowned valleys, the reef is wide, but they are narrow 

 where the slope is steep, as at the ends of the promontories. 



Professor Rollin T. Chamberlin, who made a special study of the 

 relation between the reefs and the volcanic shores of the island, and 

 who presents a report published herewith, finds that the ancient 

 barrier and fringing reefs which once sm-rounded the island and are 

 now drowned grew upon a platform which had been cut by the sea 

 and afterwards submerged and not upon the unaltered slopes of the 

 island. Thus the Darwin-Dana theor^^ does not apply to Tutuila. 

 Also, the bottom of the platform upon which these old reefs grew is 

 now submerged at least 400 feet below present sea-level, while the 

 glacial-control theory postulates a submergence of not more than half 

 that showTi by the ancient platform of Tutuik. The failure to find 

 coral upon the 8-foot elevated shore-bench around Tutuila is remark- 

 able, in \dew of the fact that it is found in the emerged limestone 

 rim of Rose Atoll, Samoa, remnants of which still project about 8 feet 

 above present sea-level. This isolated atoll is about 140 miles to the 

 eastward of Tutuila, and when the sea stood at its highest level 

 lithotliamnion and coral grew in the shallow water of the atoll rim, 

 thus indicating that the climate of Samoa was at that time tropical. 



'WTiile we were in Fiji, Coleman Wall esq., curator of the Fiji 

 Museum, kindlj^ gave us a small but excellent collection of fossil 

 lameUibranchs and sharks' teeth from the quariy in the elevated 

 limestone at Walu Bay, Suva Harbor, Fiji. These will be studied 

 by Dr. T. Wayland Vaughan. A few other specimens were collected 

 by the Director in Fiji and at Vavao, Tonga, and it is hoped that their 

 study may in the end contribute toward a determination of the age of 

 the ancient elevated coral reefs of the central Pacific Islands. The 

 matter is, however, complicated by the condition that some forms may 

 have died out in the West Indian region and tropical Atlantic and have 

 stOl survived in the tropical Pacific until more recent times. The 

 problem of the age relation of the reefs of the Pacific to those of 

 the Atlantic can be solved only by an intensive study of the conditions 

 in well-selected localities showing elevated reefs, as well as by borings 

 through submerged reefs. The fact that the ancient reefs have become 

 partly dolomitized, while those of modem times appear not yet to have 

 undergone this change, may serve to distinguish between them in 

 making borings. Especially, a comparative study must be made of the 

 elevated ancient reefs of Fiji, Tonga, and the New Hebrides. 



It may be significient that living atoll rims and barrier reefs through- 

 out the tropical Pacific are of remarkably uniform width and not so 



