222 "ALBATROSS" TROPICAL PACIFIC EXPEDITION. 



glomei-ate. Tliej both stand on a comparatively wide platform, with a 

 narrow land rim towards the sea and towards the lagoon a wide flat, sink- 

 ing in a comparatively steep slope into the general level of the deepest part 

 of the lagoon itself. 



On the western foce of the atoll, on the island of Tebukn, the beach 

 rock conglomerate ledge is limited to a small part of tlie northwest side, 

 where it is found on the very summit of the island, and there is no coarse 

 shingle on that side. This is pi-obably due to the fact that Tebuka is 

 situated to the westward of the line of action of the strong trade rollers 

 which beat incessantly on the eastern reef platform of the atoll of Funafuti, 

 and lose much of their force northward as the curve of the atoll gradually 

 trends to the westward. 



The channels on the west .side of the atoll, like the pas.sages into the 

 Paumotus in similar positions, are narrow and deep, and are cut through 

 the wide western platform on which but few islands or islets are seen. 

 South of Tebuka there is only Tebuka vili vili and Fualopa, nortli of the 

 western horn of the atoll, and to the south a couple of small islands to 

 the north of the chain of i.slands forming the western face of the soutliern 

 horn of Funafuti atoll. Fuafatu is capped with a belt of low bushes pro- 

 tecting a few cocoannt trees growing on the eastern side of the island. 



The flats and points on the west side of the atoll indicate the former 

 greater extension of the land rim which has little by little been cut down 

 to its present dimensions by the incessant action of the sea, of the trades, 

 and of the weathering due to atmospheric agencies. On the shoals which 

 extend between our anchorage and the shore, we found magnificent patches 

 of Madrepores, lai'ge heads of Porites, patches of Alcyonarians, of Millepores, 

 and of Pocillipores, as well as blocks of Pavonia and masses of Astreans. 

 The same corals we also found on other shoals in the lagoon. Great patches 

 of coral flourish on the slope of the lagoon, as well as on the knolls, shoals 

 and elevated ledges throughout the lagoon of Funafuti (PI. 222). The 

 corals on the slopes of the knolls flourish especially well when situated near 

 or opposite gaps connecting the lagoons directly with the sea. In the 

 lagoon calcareous Algas take a great development in eighteen to twenty 

 fathoms, immense masses of them extend from tliat depth towards the shore 

 into three or four fatlioms. , 



