SKEATS : CHEMICAL COMPOSITION OF LIMESTONES. oF 
which have been analyzed. It is possible that both these rocks may 
be derived from the older dolomitic limestones occurring in the cliff 
above. The remainder of the analyses in this section are those of lime- 
stones, in which the amount of magnesium carbonate does not rise 
above 4 per cent. 
Namor| Halt, [Salsa Magnennm| neha SOUTH-EAST 
OF PHOSPHATE HILL. 
SEcoND INLAND CLIFF. 
56.82 43.30 
97.6 2.4 
96.3 3.7 
96.8 3.2 
97.1 2.9 
96.1 3.9 
96.3 3.7 
97.5 2.5 
96.6 3. 
96.0 4.0 
Microscopical. No. 618.— A cavernous rock, containing hollow casts 
of Amphistegina. The only recognizable organism is a much altered 
Lithothamnion. The matrix consists chiefly of clear rhombohedral 
crystals of dolomite, a few of which show zoning by included material. 
No. 619. This appears to be a rubble rock. Small fragments of 
what looks like a dolomitic limestone are mixed with other darker lime- 
stone fragments. One small rounded augite is present, while in one of 
the fragments a piece of coral occurs, having its organic structure well 
preserved. 
No. 623. A very close-grained compact limestone, containing a few 
rhombohedral crystals. Very few recognizable organisms are present in 
this rock. 
West Waite Beacu. — This fringing reef forms a shallow cliff be- 
_ tween the levels of 500 and 400 feet at West White Beach, about a mile 
nortliwest of Murray Hill. 
