CALCAREOUS FORMATIONS OF THE SOLOMON GROUP. 549 



specimens of a small bivalve, which from its delicacy was often difficult to 

 obtain in anything like a perfect condition. Dark patches, where the Foramini- 

 ferous tests occur in increased numbers, stain these deposits ; and there are 

 imbedded numerous small rounded masses of a concretionary nature, contain- 

 ing much peroxide of iron and a little peroxide of manganese. The upper 

 surfaces of these beds are frequently marked by cracks, which have been filled 

 with a material that projects above the surface of the rock on account of its 

 greater durability ; but from the moist and semi-consolidated state of the rock, 

 these shrinkage-cracks must be viewed as of modern origin. 



It is noteworthy that I did not find any volcanic rock in situ in this 

 island. 



In concluding my description of Ugi, I may refer to the pauses in the 

 movement of upheaval which have left their marks behind them. On the 

 north-west coast, I found in the faces of the cliffs of a small sheltered cove two 

 lines of ancient erosion, the lower indicating an elevation of 4^ to 5 feet as the 

 most recent change in level, and the upper line indicating a previous upheaval 

 of 6 to 7 feet. In the interior there is evidence of a long pause in the elevatory 

 movement, when the island was about 200 feet lower than it is at present, which, 

 as already stated, has given Ugi from some points of view the profile of a broad- 

 brimmed hat. In the quiet waters of Selwyn Bay on the west coast, we find 

 testimony of an upheaval still in progress. Reefs have been elevated in mass 

 so that points of coral rock project between 1 and 2 feet above the high- water 

 level. Mr Stephens, a resident trader at Selwyn Bay, tells me that during 

 the past eight years the greater projection of these points of the reef has been 

 a matter of observation to him ; and that within that period the high-tide mark 

 has receded between 12 and 15 feet, so that some cocoa-nut palms, which 

 eight years since were within reach of the waves at high-water, are now only 

 reached by the spray. 



In the description of Treasury (page 555), I have referred to the two most 

 recent lines of ancient erosion as corresponding with the two most recent up- 

 heavals of Ugi. In both islands there is evidence of a recent upheaval of about 

 5 feet, and of anterior upheaval of about 6 or 7 feet. Such coincidences in two 

 islands situated towards opposite ends of the group, and lying about 400 miles 

 apart, would appear to indicate the general character of the movement of 

 elevation in the whole of the Solomon group. 



The Island of Treasury. 



The island of Treasury is of an oval shape, with a breadth of b\ miles, a 

 length of 9 miles, and an elevation of 1150 feet above the sea. Viewed from 



