ERRATA. 
Page 7, lines 7-10. ead as follows :— 
ZONE I. Submerged 5% to 25% of the tidal period. 
ZONE 2. Submerged 25% to 50% of the tidal period. 
ZONE 3. Submerged 50% to 75% of the tidal period. 
ZONE 4. Submerged 75% to 95% of the tidal period. 
