Archive image from page 358 of The descent of man, and. The descent of man, and selection in relation to sex descentofmansele1889xdarw Year: 1889 <&f?v Fig. 30. Xiphophorus Hellerii. Upper figure, mals ; lower figure, female. In the very distinct family of the Cyprinodontidse—inhabitants of the fresh waters of foreign lands—the sexes sometimes differ much in various characters. In the male of the Molliexesia 'petenensis,™ the dorsal fin is greatly developed and is marked '3 'Nature,' July 1873, p. 264. 14 ' Catalogue of Acanth. Fishes in the British Museum,' by Dr. Giinther, 1861, pp. 1

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Archive image from page 358 of The descent of man, and. The descent of man, and selection in relation to sex descentofmansele1889xdarw Year: 1889 <&f?v Fig. 30. Xiphophorus Hellerii. Upper figure, mals ; lower figure, female. In the very distinct family of the Cyprinodontidse—inhabitants of the fresh waters of foreign lands—the sexes sometimes differ much in various characters. In the male of the Molliexesia 'petenensis,™ the dorsal fin is greatly developed and is marked '3 'Nature,' July 1873, p. 264. 14 ' Catalogue of Acanth. Fishes in the British Museum,' by Dr. Giinther, 1861, pp. 138-151. 15 ' Game Birds of Sweden,' & 1867, p. 466. 16 With respect to this and the following species I am indebted to Dr. Giinther for information: see also his paper on the 'Fishes of Central America,' in 'Transact. Zoolog. Soc' vol. vi. 1868, p. 485.

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