FUNAFUTI. 217 



slope of the sea face seems to extend to a considerable depth, judging from 

 the buttresses exposed on the reef fiat. The coral breccia is made up of 

 rolled recent coral shingle, of pieces of coral, of shells, of sand, quite unlike 

 any breccia we have seen before, and partly changed into a hard ringing 

 limestone. Here and there I thought I could detect fragments of the old 

 limestone ledge ; of this I am not positive, it being very difficult in some 

 cases to detect the difference between the old ledge and the highly calcified 

 recent breccia, we were unable to find any outcrop of this old corallifer- 

 ous limestone at any point in Funafuti. The reef flat has been gouged 

 from the coral breccia exactly as has the old reef rock ledge in the 

 Paumotus. It supplies the materials for the building up of the island, of 

 the sand and of the shingle beaches, both on the lagoon and on the sea face. 



On the sea face, to the south of the bore, extends a high narrow 

 shingle beach which shuts off a small lagoon to the west (Pis. 222 ; 224, 

 fig. 1). This lagoon, called Taiisale, forms an isolated pear-shaped pond in 

 which the tide rises and falls (PI. 137). The inner edge is lined by man- 

 groves (PI. 137, figs. 1, 2) ; a fine section of the coral breccia, which char- 

 acterizes the outer sea dam, can be seen on the western face of the 

 lagoon (PI. 137, fig. 3). The narrow high beach thrown up across the 

 eastern point of Funafuti has shut off this pond from the sea ; huge blocks 

 of shingle of beach rock and of coral breccia have been thrown up on the 

 upper part of the outer dam. According to the testimony of the natives, no 

 water passes over this dam ; but the dam itself must be of rather hollow 

 construction, and the floor of the sink must be full of cavities to allow the 

 existing free inflow and outflow of the sea. There is a narrow fringe of 

 pisonias growing on the summit of this bank. 



The gap between Telele and Funafara Island ' (PI. 222) shows a stage in 

 the formation of such a sink as the lagoon of Taiisale (PI. 224, fig. 1), pre- 

 vious to the junction of the inner wings of the extremities of the islands, 

 and previous to the throwing up of the coral shingle dam shutting off the 

 bay forming the gap open to the sea. We shall have occasion to describe 

 the shutting off of similar bays on the sea face of some of the Gilbert and 

 Marshall Islands, and their change into closed ponds or sinks. 



» A. Chart 2983. 



