102 THE CORAL REEFS OF THE MALDIVES. 



distance of over six miles, the small island of Galandu and a few coral heads 

 alone bar the free circulation from the eastward. We passed out of Iha- 

 vandiffulu atoll through the deep pass to the south of Murdu. The deepest 

 part of the lagoon of Ihavandiffulu is thirty-one fathoms ; the majority of 

 the soundings are between twenty and twenty-six fathoms, and in the 

 northwestern part of the atoll they are considerably less, from twelve to 

 sixteen fathoms. 



Toddu. 



Plates 1. 4- 



Toddu is a small steep-to island to the north of Rasdu Atoll, about a mile 

 and a half in length by a mile in width, rising on the western edge of the 

 plateau extending to the west of North Male, and which unites Toddu, 

 Rasdu, and Ari. The greatest depth between Toddu and Rasdu is one 

 hundred and fifty fathoms. There are no soundings to the north of Toddu. 

 The island of Toddu is surrounded by a narrow reef flat somewhat wider 

 on the western face ; it resembles in every respect the larger steep-to islands 

 of the interior or outer faces of the larger Maldivian groups. 



We did not visit either Toddu or Rasdu. 



Rasdu. 



Plates 1, 4- 



Rasdu Atoll resembles in a general way Wataru Reef ; it is irregularly 

 circular in outline, somewhat more than four miles in diameter. The 

 western face is formed by a continuous reef flat. At each extremity of the 

 eastern face of the atoll is found a faro and two small islands. The south- 

 ern pass is divided by an islet; its western side is occupied by a small 

 island. The greatest depth of the atoll is twenty fathoms. The lagoon 

 is studded with coral heads, and a belt of rings and banks extends diag- 

 onally across it in a northwesterly direction from the southern pass. 



Rasdu is separated from the northern part of Ari by a channel four and 

 a half miles wide with a greatest depth of one hundred and forty fathoms. 



