— '^9A — 



Volcanic mud in which I found only a few hones of 

 hares, prohably brought there by wild cats. 



The sandy -ijortiou which comprizes more than one- 

 third of the entire island is divided into two distinct 

 parts ; a large plain consisting of sand ridges to the 

 e-ast and a narrow sand ridge on the Avestern side. The 

 sand ridges of the eastern portion, form gentle ondula- 

 tions of the surface, the highest rising to thirty feet 

 above high water mark, alternating with small valleys, 

 the general direction of both being from south to north. 

 The level of the valleys is often little above high-water 

 mark, and the eastern shore of the island is bounded 

 by an almost continuous ridge or sand-bank. 



When dug into the sand is either pure or intermixed 

 with volcanic boulders or masses of coral Avhich become 

 more numerous as we approach the volcanic part of 

 the island. The lower layers of sand even, in the in- 

 terior of the island are in process of solidification into 

 sand-stone, and the various stages of aggregation are 

 well seen from masses of agglutinated sand which crum- 

 ble beneath the fingers, to hard rock capable of being 

 used for bailding purposes and beating a very striking 

 resemblance to oolite. 



Beneath the sand which extends in the valleys to a 

 depth varying from fifteen to thirty feet, and probably 

 to a much greater depth beneath the ridges which how- 

 ever have not been explored, we find either the bare 

 vulcanic rock or thin layer of decomposed rock forming 

 a tenacious clay. It would seem that there is a gra- 

 dual descent from the ridge bounding the volcanic part 

 of the island eastv,rard to beneath the sea, the volcanic 

 rock again rising on Gabriel Island. 



The sand throughout the island presents a peculiar 

 character, which I have not been able to discover in 

 the sand at Cannonier Point or on the leeward coast 

 of Mauritius. It, is composed in gre&t part of minute, 

 fragments of coral and sea -shells with the spines of 

 sea-hedgehogs ( Echinodcrmus ;J but intermixed in. 

 very considerable proportion with a^ minute tribe of 

 sliells. E;\ch of which is mucli suiallev than a pin's 

 head, and formed of a uumbor of indopendant chani-' 

 hers like those of the NautUusi but each chamber hav- 



