TAPETEUEA. 237 



a wide triangular reef flat giving the sea free access to the lagoon, both to 

 the north and south of it. 



The sea face of the land rim, where we examined it, is flanked by a low 

 beach ; the vegetation creeps down almost to high-water mark ; little con- 

 glomerate beach rock is found at the base of the beach, with here and there 

 ridges of coral shingle, alternating with longer stretches of fine coral sand. 



The absence of land rims on the western face of several of the atolls of 

 the Gilbert Islands is a characteristic feature of that group. At Tapeteuea 

 and Tarawa, as at Onoatoa, the eastern faces form a nearly continuous land 

 rim, Avhile the western face is only protected by a sunken reef flat, covered 

 with water of variable depth, enclosing very indistinctly marked ]agoon.s. 

 These indistinct lagoons appear to have been formed, at least in the case of 

 Onoatoa and Tapeteuea, from the erosion of wide fringing reef flats once 

 occupying the summit of the shoal areas of the atolls of Onoatoa and 

 Tapeteuea, on the eastern face of which the land rim has been thrown up. 

 The wide fringing reef flats on the lagoon side of Onoatoa may be the rem- 

 nant of a former more extensive flat. A similar flat has been more care- 

 fully examined at Taritari, where I shall describe it in detail. 



Tapeteuea. 



Plates 138, figs. IS ; 223 ; 226, fig. 1. 



Tapeteuea is a triangular-shaped atoll,' its eastern face is nearly thirty 

 miles in length ; the southern face is eight miles long, with a shallow 

 passage into the lagoon. Its land rim is limited to a few sand bars. The 

 reef flat of the western face encloses an elongated triangular lagoon ; 

 towards the northern extremity of the atoll it passes into the wide fring- 

 ing reef flat flanking the western face of the northernmost island of 

 Tapeteuea. The greatest width of the lagoon is about six miles at the 

 southern face of the atoll. An indentation in the northern part of the atoll 

 forms an indiff'erent anchorage on the west coast (Peacock anchorage). It 

 is only toward the southern part of the atoll that the lagoon becomes 

 important. On the west face are two passages available for small craft. 



1 H. O. Chart 120. 



