16 PERCY SLADEN TRUST EXPEDITION 



The shore is entirely sandy and is apparently in an unstable condition, i.e. washing 

 away in some places and extending in others. The erosion seems to be greatest along the 

 northern part of the west coast, where much dead bush is standing on the present beach 

 between tide marks. (Plate 2, fig. 1.) 



To the north (N. by E.) there is a small spit of sand, which is now growing out, but 

 this is only a temporary feature, since its dryer and more landward part is covered with 

 bush killed by the sea. It has evidently been increasing outwards for some seasons and 

 has not been submerged lately, as young Toumefortia seedlings are everywhere appearing 

 on its surface. 



On the north-east the beach consists of a broad slope of sand, which in places is so 

 piled with dead Cymodocea, that it even forms small cliffs, the sand being matted 

 together by the long ribbon-like leaves*. Behind these cliffs is a ridge of sand, 

 sometimes double, and then a narrow sandflat covered with rushes, the depressions 

 between the ridges being piled full with dead Cymodocea leaves. The scrub on these 

 ridges is luxuriant and is extending out into the sandflat t. The beach round the rest 

 of the island shows little sign of alteration : the scrub is apparently flourishing, though 

 the sea at spring tides flows to the top of the beach, which is short and steep. In no 

 part was any beach sandstone found, a condition which according to Gardiner indicates 

 the absence of any continuous erosion on such beaches. 



Considering; the coast formations as a whole it seems reasonable to deduce that the 

 island is undergoing but little permanent change : evidences of quick erosion and quick 

 outgrowth are only found on the north-west and north-east, which coasts are unprotected, 

 as the reef only extends from the north-east round the south of the island to the south- 

 west. Consequently it seems probable that the rapid changes on the north-west and 

 north-east are either seasonal in character or else are due to a succession of storms, 

 and in either case merely transitional. 



The curious distribution of the fringing reef is clearly visible in the chart. The reef 

 surface was very disappointing, and after a recent visit to some reefs near Port Victoria, 

 Mahe", seemed very dead and bare. The whole flat was composed either of sand 

 covered with growing Cymodocea or of broken coral fragments, usually slightly encrusted 

 with Lithothamnia, and a boulder zone can hardly be said to exist : the buttress zone on 

 the extreme seaward face was well defined but the channels were much filled with loose 

 sand. A little live coral was found in the channels, Millepora being most abundant, 

 though Heliopora, Pocillopora and Stylopora were also present. The whole reef was 

 very sandy but the north-east portions most so, and in those regions Cymodocea was 

 most abundant. 



The vegetation of the island was poor in forms and at the time of my visit 

 (July 25 — August 1) very dried up. Completely encircling the island was a zone ten 

 yards wide, of scrub, composed largely of bushes of Toumefortia argentea and Scoevola 

 Koenigii. Inside this was a zone of varying breadth (15- — 50 yards wide) composed of 

 the same species and tangled weeds, most noticeable among which was a small creeping 

 plant, " pagote," with yellow flowers and very thorny seeds, the latter always forming an 



* Compare "Description of the Expedition," "Coetivy," Trans. Linn. Soc. Ser. n. Zool. vol. xn. (1907), 

 p. 138. t Plate 1, tig. 1. 



