64 



"ALBATROSS" EASTERN TROPICAL TACIFIC EXPEDITION. 



that the position of the reef flat has not been ascertained further west on 

 that part of the east face ; but the southeast passage indicates 5|, G, and 

 6| fathoms, wliere it probably marks the southwestern extension of the 

 eastern barrier reef, separating the lagoon from the southern plateau to 

 the south of the encircling reef. 



The western face of Manga Reva and of Tara-Vai are indented by deep 

 bays (PI. 14), which are formed by spurs running from the central ridge 

 of these islands (PI. 63, fig. 1), the remnants probably of small craters 

 which flanked the large crater, of which Manga Reva forms the western 

 rim and An Kena is the remnant of the southeastern edge, the former 

 extension of this rim being indicated by the spits uniting the base of Mount 

 Duff with Au Kena ; and by the projection of Au Kena towards the eastern 

 outer barrier reef, and of the numerous patches of coral reef off the north- 

 east point of Manga Reva towards the outer line of motus until they almost 

 unite with the barrier reef. 



Canoes in Port Rikitea. 



The western bays of Manga Reva Island are filled with fringing reefs 

 which leave here and there a deeper pass to the shore (PI. 14). The south 

 face of the bluff at the foot of Mount IVIokoto and Mount Duff is edged by a 

 flourishing fringing reef, which extends nearly half a mile on the plateau at 

 their base. The port of Rikitea is a reef liarbor formed within the large 

 fringing reef which occupies the whole of the southern bay of Manga Reva 

 Lsland. The east face of Tara-Vai and part of the east and of the west face 

 of Ajca-kanitai are also fringed with reefs. 



