. Plate 20. 



1. Entrance to Matahiva on northeast extremity of the atoll. 



2. West shore of TikaUau, looking southeast. 



.3. Land rim and gap on the southwest shore of Tikahau. 



4. AVide reef flat platform, southwest shore of Tikahau, looking southeast. 

 1-4, AV. McM. W., Phot. 



