NOTES EXPLANATORY OF LETTERING ON THE GEOLOGICAL MAPS. 123 



fresher-looking Heliopora we meet with in the platform, but, on turning over portions of it, very many 

 fragments are seen embedded on its underneath side. 



E^. Decomposing breccia sheet, exposed and being corroded. 



]\P. Mass of coral breccia 8 feet above coral platform, L5 feet by 10 feet, at base, and displaying at its 

 top fine branches of coral ; from between these the infilling is being Aveathered out. 



N^. Another mass of coral breccia, its upper part quite fantastic, 12 feet by 12 feet, at base, with very 

 manj^ forms of coral on its upper side (many of which are right side up, its base firmly cemented on the 

 main breccia sheet. The summit is 10 feet 6 inches above the outer coral platform, which, however, 

 is 4 feet 6 inches below high water (spring tide). 



0^. Large mass of Forites, 8 feet by 7 feet by 2 feet high. 



P^, Black mass of fine corals, 10 feet by 6 feet, rising 4 feet above the top of breccia sheet. 



Q2. Flat mass of breccia, 8 feet by 4 feet by 1 foot 6 inches, with coral, apparently in situ, on top. 



R^. High mass of breccia, bristling with pinnacles, and with coral embedded on top. Size 15 feet by 

 11 feet at base and 10 feet 6 inches above coral platform. 



S^. Conglomerate, in situ — same level as that on beach to north-west, weathered lumps of it lying 

 about in places. 



T^. Two big masses of breccia, in situ, with many delicate forms fractured, but in position of growth, 

 embedded among the breccia. 



U^. liarge masses of outlying breccia. 



W^. Native well. Helioprnxi occurs around the sides, in situ, 6 inches to 9 inches below high water 

 (spring tide), interspaced with foraminiferal and nullipore sand, and overlain with whitish mud, and a little 

 above the cultivated swamp land, from which it is separated by a few yards only. 



X^. Small grass fiat, composed of black sandy soil, mingled with coral and pumice fragments, instead of 

 the usual Hurricane Beach. 



Y^. The Hurricane Bank here has been driven back landwards some 10 to 20 yards, while its height 

 has also been reduced to a foot or so below the line of the pumice pebbles, which are to be seen in its end 

 sections. 



MAIN ISLAND, NORTHERN PART (Plates 10 and 11). 



A. Grass covers and mats together the rubble forming the inner slope of the Hurricane Bank in several 

 places along here, forming quite green patches of some extent. 



B. Tinojjuj'us buculatus sandstone outcrops along here, bearing a close resemblance to that occasionally 

 seen on the ocean side of this island. 



C. Tinoponis huculatus sandstone occurs along here reposing on the eroded breccia cap. 



E. Big boss of Pontes 8 feet by 5 feet by 4 feet above the breccia sheet, which it appears to pierce ; its 

 summit is 3 feet above high water. 



F. Large cakes of breccia, up to 6 feet by 4 feet by 1 foot 6 inches, are lying on the Hurricane Bank, 

 where they appear to have been carried on being removed from the breccia sheet by the waves. 



G. Some small bosses of Porites firmly fixed on the platform here. 



H. Many large blocks of breccia occur among the beach rubble along the Hurricane Bank. 



J. Large mass of breccia 10 feet by 7 feet by 5 feet, with many kinds of coral, small and larger, near 

 and forming its present summit ; the spaces between the corals are filled in with small debris firmly 

 cemented into one mass. 



K. Several specimens of Porites seen on different parts of the beach apparently in situ. 



L. Outer channel very angular along here. 



M. Boss of breccia in situ, 4 feet above high water on the line of the outer part of corrosion zone. 



R 2 



