ROCKS ANCIENT AND MODERN. 183 



structure of the island. All along the south side of the 

 island there is also a slight fringe of coral, which caps 

 the granite but never extends inland for more than a few- 

 yards. 



The accompanying photograph shews an admirable 

 section taken on the south side of the island, near our 

 landing place, of the granite below, and the coral over- 

 lying it in a capping about six feet deep . As far as we were 

 able to observe, there was not the slightest trace of coral 

 along the western shore of the island, which was dis- 

 tinguished by sandy beaches and low dunes, and it is 

 worthy of mention that it was on this side, at a spot 

 where the soil seemed of a more clayey or sandstoney 

 nature, that we one day came upon the only natural pool 

 or spring of fresh water. There were also some fairly 

 extensive brackish ponds in this neighbourhood, which 

 had been formed between the sand dunes and the grass- 

 covered granite slopes inland. 



Round the muddy margins of these pools some waders 

 were busy feeding ; and we noticed a large blue-heron 

 (Ardea herodias) and a kingfisher [Ceryle alcyon) ; while in 

 some thick mimosa scrub near by, we missed securing 

 one of the only two examples seen during our visits to the 

 island of a very beautiful dove. These doves belonged 

 to the genus Zena'ida, with which pretty name Sir 

 Frederic Johnstone had christened the yacht in which 

 we visited Blanquilla. 



From what has been said above as to the position of 

 the old coral reef and its structure, it would seem 

 highly probable that, geologically speaking, Blanquilla 

 has only recently been upheaved from the sea, although 

 its foundations consist of the most ancient types of rock 

 (Precambrian) . 



Close upon one hundred and eighty miles nearly due 

 east of it, lies the island of Grenada ; and to the north of 

 this, the three islands of Martinique, St. Lucia and 

 St. Vincent are distant from Blanquilla some two 

 hundred and forty miles in north-easterly direction. 



