404 J. STANLEY GARDINER. 



formed of sand ; a few rocky banks, it is true, do occur, but most of these are obviously piled 

 up by the waves, and there are extremely few, if indeed any, pinnacles, undoubtedly belonging 

 to the elevated rock. Fresh islands and sand-banks are not infrequent on the west side, and 

 probably all the land in this position has been formed by the heaping up of sand. Further, 

 the relatively small reef patches which form the west rim, as compared with the east, are 

 remarkable, everything in conjunction pointing to a much less perfect condition of the west 

 side as compared to the east, when the original elevation, that formed so much of the land 

 of the Maldive banks, took place. 



My companion, Mr Forster Cooper, who investigated the lagoons of these atolls by sound- 

 ings and dredgings, reported singularly little change in them. The depth nowhere had 

 decreased, but an increase was rather indicated, though on account of the difficulty of accurate 

 fixation it was impossible to afford definite proof of the same. Most of the larger interior 

 reefs are faro, and even smaller ones of 150 — 200 yards in diameter have the centre rather 

 lower. None definitely showed growth. All have precipitous slopes with an area of decaying 

 coral masses around them. 



Only ten passages into the different lagoons were examined, in three of which distinct 

 shoaling was found. In seven an apparent constriction seemed to be taking place by the 

 outgrowth towards one another of points from the neighbouring reefs. Upgrowths of new 

 shoals near the inner ends of two passages occurred, a most unusual feature at the present 

 day. No areas, covered with living corals, such as might form shoals, were met with in the 

 interior of the banks, but isolated massive colonies of Goniopora and Alveopora were frequently 

 dredged, and some parts were much covered with the living and dead coralla of the solitary 

 Diaseris. Dendrophyllia, which of all the corals was most frequently dredged in the living 

 state, seemed for the most part to be confined to passages and current-swept areas. 



VIII. North and South Nilandu (Fig. 105). 



I cannot do more than call attention to a few points in these two atolls, which in their 

 topography are intermediate between the more open banks and the more perfect rings of the 

 Maldives. The characters of both banks are so admirably shown in the charts that it is 

 only necessary for me to refer to the shoals within their lagoons. These in different situations 

 show in their characters every grade between the similarly-situated reefs of Miladumadulu 

 and those in the most enclosed parts of Suvadiva or North Mahlos, from reefs that are in- 

 dubitably growing outwards to others that are as certainly being removed by solution and 

 other agencies. All the shoals on our course seemed to be correctly placed in both atolls, 

 but in the south of the northern atoll we found in addition six uncharted shoals and three 

 others in which growth was particularly strongly marked. Most of the shoals within the 

 encircling reefs of the atolls were represented in the chart as presenting flat tops without 

 land. All over 200 yards in breadth that we examined — twelve in number — in addition had 

 velu, definite little lagoons (Fig. 105), whereas a central pool was only charted in a single 

 one. In the southern atoll the same prevalence of velu was noticed, and indeed their presence 

 in all the larger shoals of either atoll appears to be the rule. Beyond this a considerable 

 enlargement was found in all the charted velu that we passed, whether in the lagoon or 

 rim reefs. 



