REPORT ON DREDC4m(l AT FUNAFUTI. If) 5 



It appeared from such evidence as we were able to obtain that tlie material was 

 fairly coarse near the base of the cliff, and gradually became finer at the deeper 

 levels. What surprised us most was the depth to which living Lithothamnion of the 

 encrusting type could be traced, viz., to at least 200 fathoms. It might bo thought 

 that such pieces as we collected from these deep levels were not in situ, but had 

 recently rolled down to the foot of the submarine cliff from higher levels, but this 

 could hardly have been the case for (l) in a great many cases the Lithothamnion 

 from these deeper levels was alive ; (2) we found living specimens at these great 

 depths after spells of fair weather, during which time it is improbable that many 

 pieces of this organism would roll down the cliff face from shallower levels ; (3) 

 many of the living specimens of^ Lithothamnion, from between 100 and 200 fathoms, 

 showed fresh fractures as though they had been broken off in situ by our chisel. 

 Although there was so much sand and pteropod ooze near the 200-fathom level, 

 the bottom Avas largely formed of fairly hard rock between this level and the base 

 of the submarine cliff at 140 fathoms. Such at all events was the experience of the 

 Expedition of 1897. 



Ah regards the distribution of the four chief reef- forming organisms on the ocean- 

 ward slope of the atoll (1) the foraminifera, (2) the Lithothamnion, (3) the Halimeda 

 and (4) the corals, the free foraminifera, living at moderate depths on the ocean 

 slope of the reef, are specially characterised by Cycloclypeus Carpenteri. This seemed 

 most abundant at about 80 fathoms. Mr. F. Chapman states*: — "As regards the 

 last-named species, C Carpenteri, it is interesting to note its occurrence at foui' 

 localities around Funafuti, viz., Pava, Funamanu, Tutanga and Fuafatu. It has a 

 range in depth of 30 to 200 fathoms. At 50 to 60 fathoms both the megalospheric 

 and the microspheric forms occur, form A greatly preponderating. At 80 fathoms 

 form B (the microspheric or large discoid form) was most frequently dredged up alive 

 by Professor- David." Possibly its almost entire absence from the lagoon (where 

 only a very few shells of this genus were observed by us) may be due to this genus 

 frequenting mostly depths greater than any in the lagoon, the maximum depth of 

 which is 30 fathoms. If this conclusion be correct it should have an important 

 bearing upon the evidence supplied by the core of the diamond-drill bore, as the 

 presence of much Cycloclypeus in the reef rock of the bore would indicate that such 

 a rock had probably been formed at a depth greater than 30 fathoms, t 



* 'Linnean Soc. Journ.,' Zoology, vol. 28 (1900-03), p. 394. 



t [This species of Cycloclypeus (see Dr. Hinde's Report, Section XI, pp. 228-291 and 318) occurs 

 occasionally, bnt with long gaps, in the core from 570 feet (its first appearance) down to about 1070 feet. 

 On this point Dr. HiNDE writes to me : " Though Ciidodjipeni appears to be fairly common now on the reef 

 slopes between 30 and 200 fathoms, in the cores it is only met with in any numbers between 660 and 740 feet 

 from the surface. ^Ir. F. Chapman seems disposed to consider the occurrence of this genus at such depth 

 on the present reef slopes as an argument, that those in the cores lived at similar depth (' Liim. Soc. Jour., 

 Zoology, vol. 28, pp. 21-26), but it does not seem to me that these unattached forms are of much value as 

 indications of depth. Anyhow, though at Funafuti they do not occur (so far as at present known) at a less 



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