12 C/iriatmas Island, 



uppermost of the inland cliffs above described. In other places 

 it passes into the inland cliff by a more gentle slope. The actual 

 margin is usually marked by a belt of limestone pinnacles of 

 greater or less "width. Another notable feature is the occurrence 

 on the northern and eastern borders of several peculiar hills, the 

 long axis of which lies parallel to the edge of the plateau. 



Of these hills Gannet Hill and Phosphate Hill (see Map and 

 rigs. 4 A, E) may be taken as typical. If the former be approached 

 from the westward, it will be found that the plateau slopes very 

 gently up to its foot; then there is a steep slope, from 50 to 60 feet 

 high, and above this a level surface from 100 to 200 yards wide. 

 On the outer edge of this, and rising abruptly from it, is a belt of 

 limestone pinnacles, some of which are more than 10 feet high; 



FIGURE 4. 



A slo;te streujr. ^Uh (.locks ^ ninjxades of dolo^vCu ii^estono 



of Fhasjihate ojlime^' '>i,^^ 



Piiteau ^ '^ ^^-v_ ''■f''-<« siorve 



• ' " ( 'yfup.er inland cliff ) 



W r'------''"-"-'---'----'------- ■ ■''■^•- ■ ' ■■ ■ ■'- ' ■■■ ■- — ■ ■ ■■ ■ ■■ . '""^ E 



B 



GANNET HILL 

 HilL couired u;dk Uock^s oj phostihale of Itme 



^ ■'mmm::-mm^^^ :■ ^ __________ — ..^ ^ — _____ ^ _ ^ 



i^HOSPHATE HILL 

 Q low dbff oj dolonitic Umestunt 



up-fier terrace 



NORTHLRN EDGE OF PLATEAU 



beyond these is a steep slope covered with a wild confusion of 

 blocks and pinnacles of limestone. The top of the hill is about 

 850 feet above the sea, while that of the plateau within is some 

 50 feet lower, at least at the northern end. Towards the south 

 the difference becomes less and less, till the ridge completely 

 disappears. The inland slope is strewn with blocks of phosphate 

 of lime, and the whole, as far as the belt of pinnacles, is covered 

 with a forest of lofty trees ; the outer slopes are clothed with 

 thorny creepers and low trees. 



Phosphate Hill^ which forms the north-eastern angle of the 

 plateau, is much more extensive, and in the northern part at least 

 there is no distinct belt of pinnacles forming its outer border, but, 

 instead, a fairly gentle slope, terminating in a low limestone cliff, 

 below which is the level upper terrace. The whole of the summit, 

 as well as the northern and western flanks of this hill, is thickly 



