ARHNO. 323 



and change parts of it next to the land rim into a reef flat, continually 

 becoming broader. 



The bay of the northeastern extension of the lagoon is more than a 

 mile wide. The islands on its northern face (PI. 181, figs. 3, 4; 228, fig. 4) 

 are separated from the islands to the east of Dodo Pass by a long stretch 

 of reef nearly awash at low water; on its outer edge a line of heavy 

 breakers is pounding and constantly throwing material across the flat 

 into the inner part of the lagoon. 



The sea face of Terranova, the principal island on the eastern side of the 

 atoll, is nearly fourteen feet high ; it consists of coral boulders derived from 

 the outer narrow reef platform thrown up to form a steep beach. The summit 

 of the beach is fully fifty feet in width ; large masses of coral have been 

 rolled inland across the whole width of the island to form the spits in the 

 northeastern lagoon. It is evident from the position of the masses of coral 

 boulders tliat the island forming the eastern face of the northeast branch 

 of the lagoon has been built up by material derived from the outer eastern 

 face, as has been formed the high steep bank of the east shore of Terranova. 

 The spits on the western face of Terranova, once lines of boulders extend- 

 ing across a wide reef flat, have been excluded from the sea by an outer 

 dam; this has obliterated all traces of the gaps existing between the 

 islands once forming the east face of Arhno. The lines of rocky ledges on 

 the lagoon side remain to indicate the gaps, closed by the formation of a 

 shingle dam as the nucleus of the land rim of the east face of Arhno. The 

 eastern face of the northeastern extension of the lagoon is occupied by 

 Terranova, a narrow and slightly hook-shaped island. The lagoon beach is 

 composed of fine, slightly reddish coral sand, with here and there a stretch 

 of beach rock made up of a conglomerate of broken corals cemented with 

 fine coral sand. Near the southern extremity of the island on the lagoon 

 side is a spit composed of broken angular masses of dead coral. This mass 

 is underlaid by beach rock, and at this point the lagoon beach is from six 

 to eight feet above low-water mark. About fifty feet inland, back of the 

 lagoon beach, the lowest land of the island is found ; that is, there exists 

 immediately behind the lagoon beach a long trough-like depre!s.sion running 

 parallel with the lagoon beach nearly half the length of the island. There 



