34 bulletin: museum of comparative zoology. 



were deposited, mixed with accretions derived from the tests of animals 

 provided with calcareous shells ; or again great stratified limestone de- 

 posits were found which are comparable to the compact limestone strata 

 of the Singatoka area (Plate 3, Figs. 1 and 2), and which, like them, 

 may be non-fossiliferous, while others again may contain scattered corals 

 and shells ; and that these bedded rocks came within the reef-building 

 zone, either by uplifts like those traced to-day on the Vatu Leile and 

 Vatu Vara cliffs ; or by their own increase in thickness during a period 

 of stable equilibrium ; or again by the joint results of elevation and 

 accretion. Much of the limestone mass shown in the sections of Mango 

 and Tuvutha, 1 (Plates 2 and 3, Figs. 3 and 4) is doubtless (in its 

 lower part) composed of compact bedded limestone. 



After the first period of elevation succeeded periods of rest, during 

 which such masses as the second "terrace" of Yathata and Tuvutha 

 were formed. While Yathata, Tuvutha, and other islands show broad 

 flat land at this stage, Vatu Vara shows but an incipient " terrace " 

 structure. This might be accounted for if Vatu Vara was building on a 

 very steep slope. In this case the corals could advance but slowly on 

 their own talus, while if the other islands had broad fiat patches of land 

 to build on, or craters, they could easily assume their present great exten- 

 sion at this level. 



From the next point of upheaval (the 400 feet level) to the present 

 sea-level, the evidence points to smaller upheavals, with intervening 

 periods of protracted rest. One of these periods of rest was of much 

 longer duration than the others, and marks the 250 to 300 feet level. 



The Metamorphism of the Limestones. 



The limestones near Suva are generally interstratified with the " Fiji 

 soapstone," and this is especially noticeable in the wedge-shaped mass at 

 Walu Bay. This superimposing of the " soapstones" upon the calcareous 

 rocks has suggested 2 the possibility of the induration of the limestones 

 of Lau by exposure and water soakage, and that the immunity of the 

 Suva limestones from this metamorphism is due to the impervious char- 

 acter of the " soapstone " cap. Even a cursory examination of the Singa- 

 toka River area, where limestone occurs in all varieties of hardness and 

 compactness, shows this not to be the case. There we have an escarpment 



1 The volcanic peak drawn as the base of the summit of Tuvutha, Plate 3, 

 Figs. 3, 4, is merely provisional, as there is no direct evidence of its being such. 



- J. Stanley Gardiner. The Coral Reefs of Funafuti, Rotuma, and Fiji. I 'roc. 

 of the Camb. Thilos. Societv. 1898. 



