[255] Ehrenberg (54).
[256] Noll (95) p. 248.
[257] Hooker, J. D. (44) vol. I. p. 503.
[258] Murray, J. and Renard (91) p. 208.
[259] Nansen, Daily Chronicle, Nov. 2, 1896.
[260] Schütt (93) p. 10.
[261] Ehrenberg (36) p. 77.
[262] Cayeux (92), (97).
[263] Shrubsole and Kitton (81).
[264] I am indebted to Mr Murton Holmes for specimens of these London Clay Diatoms.