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Show a cross between four species, namely, tlie Mallard, Spotbill, Pintail, and New-Zealand Duck. In conclusion, Mr. Bonliote said that it was far too early in his experiments to do more than quote the bare facts; but that, from the facts he had laid before them, there could be no doubt that hybridisation tended to produce variations that followed 011 the lines of the pcecilomeres, and that in so doing resemblances were shown towards other species that had no part in their parentage. 1 9 0 5 . ] MR. G. A. BOULENGER ON FISHES FROM LAKE CHAD. 1 5 1 Mr. G. A. Boulenger, F.R.S., exhibited a series of Fishes from Lake Chad and the Shari River, collected and presented to the British Museum by Capt. G. B. Gosling, and offered the following remarks:- The fact that so many species of fishes are common to the Nile and the Senegal-Niger, now so widely separated, has long ago led ichthyologists to assume a former communication, in times geologically recent, between these river-systems, and to regard Lake Chad as probably representing the dwindling remains of a series of lakes by which this communication was effected. But, with the exception of a series sent to the Paris Museum a few months ago and not yet reported upon in a published form, the fishes of Lake Chad and the rivers that flow into it had never been collected. Thanks to Capt. Gosling, we are now able to draw up the following list of 23 species, belonging to 7 families :- M o rm y r id .l . Petrocephalus bane Lacep., Mormyrus caschive ITasselq. (jubelini C. & V.), Hyperopisus bebe Lacep., Gyrn-narchits niloticus Cuv. C i ia r a c in id .e . Hyclrocyon brevis Gthr., Alestes baremose Joannis, A. dentex L., A. nurse Rupp., Distichodus rostratus Gtlir., D. brevipinnis Gthr., Citharinus citharus Geoffr. C y p r in h l e . Labeo horie Heck. (senegalensis C. <fe V.). Silurid/E. Clarias lazera C. & V., Heterobranchus senegalensis C. &, V., S'chilbe mystus L., Clarotes laticeps Rupp., Bagrus bayad Forsk., S/jnodontis clarias L., S. batensoda Rupp., S. serratus Riipp. S e r r a n id ,e . Bates niloticus Hasselq. C ic h l iDjE. Tilapia nilotica L. T etrodont id.e . Tetrodon fahaka Hasselq. All these species, without a single exception, are common to the Nile and the Niger, thus realising in a most striking manner our anticipations. The following papers were read :- |