INDIAN OCEAN. 243 



fringed ; he states that all these islands are formed of granite 

 and quartz, that they rise abruptly from the sea, and that 

 1 coral-reefs have grown round them, and project for some 

 distance.' Dr. Allan of Forres, who visited these islands, 

 informs me that there is no deep water between the reefs and 

 the shore. The above specified points have been coloured 

 red. Amir antes Islands : the small islands of this neigh- 

 bouring group, according to the MS. account of them by 

 Captain F. Moresby, are situated on an extensive bank ; they 

 consist of the debris of corals and shells ; they are only about 

 20 feet in height, and are environed by reefs, some attached 

 to the shore, and some rather distant from it. — I have taken 

 pains to procure plans and information regarding the several 

 islands which lie to the S.E. and S.W. of the Seychelles; 

 from accounts given me by Captain F. Moresby and Dr. Allan, 

 it appears that the greater number — namely, Platte, Alphonse, 

 Coetivi, Galega, Providence, St. Pierre, Astova, Assomption r 

 and Glorioso — are low, formed of sand or coral-rock, and irregu- 

 larly shaped ; they are situated on very extensive banks, and 

 are in connection with great coral-reefs. Galega is said by 

 Dr. Allan to be rather higher than the others ; and St. 

 Pierre is described by Captain F. Moresby as being cavernous 

 throughout, and as not consisting of either limestone or 

 granite. 'These islands, as well as the Amirantes, certainly 

 are not atoll-formed, and they seem to differ from all other 

 groups ; I have not coloured them ; but probably the reefs 

 belong to the fringing class. Their formation is attributed 

 both by Dr. Allan and Captain F. Moresby, to the action of the 

 currents, here exceedingly violent, on banks which no doubt 

 have had an independent geological origin. They resemble 

 in many respects some of the islands and banks in the West 

 Indies, which owe their origin to a similar agency, in conjunc- 

 tion with an elevation of the entire area. In close vicinity to 

 the above several islands, there are three others of an ap- 

 parently different nature ; first, Juan de Nova, which appears 



