100 THE CORAL REEFS OP THE MALDIVES. 



The eastern face of Miledu (PL 52, fig. 2) is flanked by coarse coral 

 shingle beaches; the northern point is buried in large coral bcmlders. 

 Miledu, Tukandu, and Marandu are all steep to, and characterized by a 

 belt of large boulders on the eastern face. The finest boulders are on 

 Tukandu (PI. 53), towards the southeastern extremity and on the eastern 

 point of Marandu. The reaches of boulders are separated by sand or coarse 

 shingle beaches. On the western sides the islands are bordered by high and 

 steep sand beaches. 



Ihavandiffulu. 



Plates 1,2; 8 a, figs. 1, S ; 54, 55, fig. 1. 



Ihavandiffulu (Pis. 1, 2), the northernmost atoll of the Maldives, is irreg- 

 ularly rectangular in shape, about thirteen miles in length, and seven in 

 width ; its trend is from southeast in a northwesterly direction. It is 

 separated from Tiladummati by Gallandu Channel, about two and a half 

 miles in width at its narrowest point and with a depth of two hundred and 

 fifty-one fathoms in the centre. A sharp ridge must connect Ihavandift'ulu 

 and Tiladummati, as both to the east and west are found soundings of over 

 six and seven hundred fathoms (PI. 1). 



The southern horn of Ihavandiffulu is occupied by Digufuri, an elon- 

 gated, pear-shaped reef, with wide flats at the two extremities enclosing a 

 shallow lagoon, occupying the central area of the reef flat. The outer rim 

 of this flat is edged by a low wall of small coral boulders like that which 

 fringes Makunudu. A few ill-defined sand-bars rise on the outer belt of 

 the northern face of the. reef flat towards lhavandu Island. 



North of Digufuri the concave western face of Ihavandiffulu is bordered 

 by a reef flat from one to two miles in width ; its northwestern horn sweeps 

 eastwardly to form the northern boundary of the atoll. On the sea face of 

 the western reef flat extends a long chain of narrow islands and islets set 

 back somewhat from the outer edge of the reef flat (PI. 54, fig. 2). The 

 western faces of these islands and islets are bordered with sand or coarse 

 shingle beaches with short reaches of beach rock at the base of the beaches. 

 A belt or low wall of small, weathered, angular boulders similar to that of 



