REPORT OX DRED(4TXU AT FUNAFUTI. 157 



us t(T differentiate between the sliallow-water Lithothamnion and the deep-water 

 Lithothamnion , so tliat in tlie case of encrusting forms in the core from tlie 

 diamond-drill bore one might lie able to state (A) whetlier tliose met with in 

 the upper part of the bore can be referred to shallow-water types, while those 

 encountered lower down in the bore belong to deep-water types, or (B) whether 

 shallow-water types of Lithothamnion predominate in the core from top to bottom, 

 as one would expect to have been tlie case in the event of subsidence ? This appears 

 to us to be an extremely important point. As stated in Mr. Finckh's Report (and 

 his observations are confirmed by all of us), the branching and knobby varieties of 

 Lithothamnion are exclusively shallow water in habit at Funafuti, whereas the 

 encrusting form is both shallow and deep water in habit. It follows tliat the 

 evidence supplied by encrusting Lithothamnion alone would be negative and incon- 

 clusive, l)ut if the branching or knobby type of Lithothamnion were found in sitn in 

 the core from the deeper levels, this would be most valuable evidence as to original 

 shallow- water conditions of deposition of such portions of the reef rock.* 



We should like here strongly to emphasise the fact that, although most of our 

 deep-sea dredgings were made off the western side of the atoll where the branching 

 forms of Litliothamnion are exceedingly abundant, we never once obtained a single 

 live specimen from depths below 10 fathoms. Neither did we recognise remains of 

 this among the sand and rubble on the submarine slopes of the reef The latter 

 fact seems strange and may have been due to imperfect observation, or possibly to 

 the fact that the fragments may have been so comminuted as to be chiefly in the 

 form of fine sand, in which case it would have been difficult, in the field, to 

 distinguish them from grains derived from encrusting types of Lithothamnion. That 

 point we may expect to be settled by Dr. Hinde's examination of the core. 



(3) Ilalimeda. Miss Ethel S. Barton (Mrs. Gepp) has described,! under the 

 name otH. laxa, n. sp., a specimen which we dredged alive from a depth of 35 fathoms 

 off Tutanga Islet, on the south-west portion of Funafuti Atoll,;}; We also obtained 



* [On this point, as suggested by Professor David, I consulted Dr. Hinde, of whose kind reply the 

 following is a precis. " I was unable to do more than indicate the branching, nodose and incrusting modes 

 of growth of the Lithothamnion in the cores, and cannot say definitely whether these correspond Avith the 

 similar growth-forms from the reef slopes. But branching forms certainly occur abundantly at considerable 

 depths of the core ; for instance, Ijetween 926 feet and 9i5 feet from the surface, the rock in places is largely 

 made up of this form, but for the most part the pieces are mere fragments, which cannot be more precisely 

 determined. Professor David remarks on these cores, that the abundance of nullipore of a branching type 

 in the rock is specially noteworthy. In the cores lietween 991-1007 feet I have noted branching 

 Lithothamnion apparently in position of growth, and in the same core found specimens of the reef corals 

 Pocillopora and Stylophora. Also in cores at 1066-1072 feet there is a cast of an Astrsean coral, overgrown 

 with thick nodose layers of lAthothamnion." — Ed.] 



t 'Linnean Soc. Journ.,' Botany, vol. 34, 1900. 



X In a later work, however (Monographe LX, ' Uitkomstcn op Zoologisch, Botanisch, Oceanographisch 

 en Geologiseh Gebied. Siboga-Expeditie,' p. 23), she regards H. laxa as " an extreme variation," but one 

 which comes quite clearly within the limits of the species //. gracilis. 



