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Show 1884.] ON RACES AND HYBRIDS A M O N G THE SALMONIDCE. 17 from St. Vincent, but is I think sufficiently distinguished following characters :-the fine acute spines of the penultimate and terminal segments are here replaced by conical or rounded tubercles, and the posterior half of the antepenultimate segment, which is represented as smooth and entire in G. bradyi, is granulated in G. trachurus on the dorsal surface and minutely spinulose on the posterior margin. EXPLANATION OF PLATE I. Fig. I. Callianassa martensi, sp. n., male, x H diam. (p. 13). la. Frontal region and antennae of the same species, showing the form of the frontal spines, X 3 diam. 1 b. Extremity of one of the legs of the third pair, showing the form of the produced posterior lobe of the penultimate ioint and of the dactylus, X4diam. 1 c. Terminal segment and uropoda, x 3 diam. 2. Terminal segment and uropoda of C. mauritiana, enlarged. 2 a. Larger chelipede of Callianassa mauritiana, Miers, natural size. 3. Gonodactylus trachurus, v. Martens, adult male, X 2 diam. (p. 16). Sa. Eaptorial limb (second maxillipede) of the same species, x 3 diam. 4. On Races and Hybrids among the Salmonidce. By FRANCIS D A Y , F.Z.S. [Received December 24, 1883.] In March 1882 I laid before the Linnean Society the results of some observations which I had made on the British Salmonidse, tending to show that the number of species existing in these islands had been unduly multiplied by local races or varieties having been considered species. In the month of December I communicated to this Society some facts respecting the hybridization of Salmon and Trout, and likewise adverted to Sir J. Gibson-Maitland, Bart., F.L.S., having kindly instituted, on November 15th, 1882, three additional experiments upon crossing different forms of Charr, or Charr with Trout, the results of which, so far as they have gone, I propose describing this evening. I have also to thank Sir J. Gibson-Maitland for permitting me to take examples of all the various crosses which have been made at Howietoun (many of which are on the table for examination), while he has also freely furnished m e with information on all points, and access to his notes. There are likewise a series of Salmonidae hatched in the great International Fisheries Exhibition, from eggs brought from Canada by Mr. Wilmot, the Canadian Commissioner, who gave me specimens at short intervals, so that I have a connective series. I shall have to refer to a pair of fine Trout sent to me in ice from the Otago Acclimatization Society, through the kind offices of Mr. Arthur, which are now preserved in spirit in the Economic Fish Museum at South Kensington. Lastly, I shall describe the Salmo gracilis of Couch (? Cuv. & Val.), a local race which I had the PROC. ZOOL. Soc -1884, No. II. 2 |
