Fossil plants, Vol. 1: [A text-book] for students of botany and geology - A. C. Seward

[175] Rothpletz (96), p. 909, Pl. XXIII. fig. 4.

[176] Challenger (85) passim. Schütt (93).

[177] Phillips W. (93).

[178] Kippis (78) p. 115.

[179] Darwin (90) p. 13.

[180] Rothpletz (92).

[181] Walther (88).

[182] Cohn (62).

[183] Murray, G. (95²).

[184] Thiselton-Dyer (91) p. 226.