320 "ALBATROSS" TROPICAL PACIFIC EXPEDITION. 



such a land rim while the atoll is subsiding. The evidence we have 

 shows a certain amount of elevation, indicated by the position of out- 

 liers and outcrops of the underlying base or fundament upon which the 

 loose material has accumulated. If the land had been subsiding, this 

 material must in the end have been washed off from its surface and 

 deposited either on one side or the other of the face of the atoll. 



According to the chart, many shoals and flats exist or are forming 

 in the lagoon of Wotje, especially in the northern part along the whole 

 length of the land rim (PI. 228, fig. 1). Where we steamed past shoals 

 and flats their position was marked by long lines of breakers, separated 

 by greenish bands of shallow water, indicating the intervening sandy flats. 

 The amount of sand continually in motion on these flats is considerable, 

 and shows how fast the coarser materials, the boulders and the blocks 

 thrown up on the beaches, are pounded and ground into sand. In an 

 enormous lagoon like Wotje (thirty miles by fifteen), the northern side 

 of the lee face is, of course, subject to the influence of the northeast 

 trades. The very outlines of the islands of the land rim on the weather 

 side of the atoll indicate how regular the action of the trades must have 

 been in throwing up this mass of material upon that face of the atoll. 

 As seen from the south, across the lagoon, the islands appear like rec- 

 tangular blocks of nearly uniform size, with rounded corners, separated 

 by gaps. The islands are all edged on the lagoon side with glistening 

 white coral sand beaches. They are fi'om five to six feet high. As we 

 steamed out of Schischmarev Pass, we observed on the second island to the 

 west a huge boulder, a mass of Porites, thrown high up on the reef plat- 

 form, similar to those found on the reef flat of the sea face. Several hauls 

 made by the Kramer machine to limited depths outside of the atoll brought 

 less pelagic material than in the lagoon. This may be due to the great 

 disturbance of the surface outside of the lagoon, where the trades drive 

 the pelagic material to a considerable depth, while in the lagoon the 

 pelagic material lives in comparatively smooth water ; a large proportion 

 of the surface of the atoll is sheltered at all times during the prevalence 

 of the northeast trades, or in calm weather, or during the short time that 

 westerly winds prevail. 



