152 PROF. T. W. EDGEWORTH DAVID, MR. G. H. HALLIGAN, AND MR. A. E. FINCKH. 



composed chiefly of detrital Halimeda with fragments of shells, intermixed with a 

 little seaweed. Dredgings made elsewhere in the lagoon at depths not exceeding 

 12 fathoms showed that coral detritus (mixed with that of Lithotliamnion) pre- 

 dominated in the sand-like material, giving place to Halimeda detritus, as already 

 stated, at greater depths. Nowhere was any solid rock met with inside the lagoon 

 except along the shore line or at the shoals and coral patches where the depth did 

 not exceed a few fathoms. 



As regards the dredgings outside the reef, we used ordinary iron dredges, a 

 powerful and heavy toothed iron crown, kindly supplied by Professor Haswell, sand 

 pumps, a conical steel bucket and a chisel-edged drill, together with hemp tangles. 

 The first two appliances could not be worked satisfactorily with the power at our 

 disposal, the result of attempts to drag the dredges or the iron crown being that 

 sooner or later the rowing boat became firmly anchored by them, and eventually these 

 appliances and much rope were lost, though in the meantime they enabled us to secure 

 a fair amount of useful material. 



As regards the collections of sj^ecimens from the submarine slope of the atoll, we 

 were most successful when working with a heavy steel chisel suspended by a strong 

 but light rope. The chisel weighed about 80 lbs. and a tangle of hemp was attached 

 to it in the mauner re})resented on Plate 19. By alternately raising and dropping the 

 chisel, by means of the rope, pieces were broken ofi' in situ from the steep face of the 

 reef, and some of them were arrested and retained by the tangles as fast as they were 

 loosened by the chisel from the surface of the submarine slope. It was found possible 

 to carry on this work successfully to a depth of 200 fathoms, but at that the 

 task of hauling up by hand the heavy drill and tangles to the boat involved serious 

 loss of time, and in rough weather was difficult to accomplish. A heavier drill would, 

 we are sure, have been more successful, but the power available in a rowing boat is, 

 of course, limited, and it is impossible for oarsmen to drag a heavy weight along a 

 bottom like that of a reef face at depths of more than 200 fathoms. The two foremen, 

 Wells and Hrrbert, brought from Sydney for the lagoon boring operations were 

 invaluable here, as they were both sailors and good oarsmen, but the boat was heavy, 

 the weather was hot and the work was hard and continuous, so that the progress 

 often seemed slow and the results altogether disproportionate to the labour expended. 



Tlie conical steel bucket (Plate 19) when pulled up from a depth of 200 fathoms was 

 frequently found to be full of sand-like material largely formed of comminuted 

 fragments of coral about the size of peas together witli foraminiferal shells and joints of 

 Hali>n.eda. Among the former Cycloclypeus was abundantly I'epresented. We obtained 

 both live and dead specimens of this type on the ocean side of the reef, at depths 

 varying from 46 to 200 fathoms, but in the lagoon its shells were extremely scarce 

 and no live specimens of this genus were observed. Similar sand and small fragments 

 of coral were also obtained at depths, not exceeding 200 fathoms by some of us 

 (Messrs. Poole, Woolnough, and David) off'Pava and Fuafatu ; at Pava calcareous 



