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Show 879.] ON TRIGLA POZCILOPTERA AND TRIGLA HIRUNDO. 179 10. O n the Identity of Trigla pmciloptera and T. hirundo. By FRANCIS DAY, F.Z.S. [Received February 17, 1879.] (Plate XVIII.) While at the Westminster Aquarium in the month of October last year, m y attention was drawn to some small but beautiful Gurnards that had recently been obtained from Southend. The colours on the inner side of their pectoral fins did not coincide with that shown in any British example; and the presence of a large, black, oval blotch, covered with light blue spots, seemed to render it probable that they might be the "Little Gurnard" (Triglapoeciloptera)-a species which neither Yarrell nor Couch were so fortunate as to obtain1. I therefore asked Mr. Carrington, the naturalist to that establishment, to preserve any examples that died, in order that I might have the opportunity of ascertaining, first, if they belonged to the species I supposed, and, secondly, if such specimens were or were not the young of another form. I have now to record m y thanks to M r . Carrington for six excellent examples of the "Little Gurnard " (varying from 2*0 to 9*8 inches in length), which, so far as I a m aware, has not previously been recorded from the waters of Great Britain, although a fish two inches in length has been reported to have been captured in Ireland, but, as I shall presently show, was either wrongly identified or erroneously described. This fish has been recorded in several works (Cuv. & Val. iv. p. 47 ; Thompson, P.Z.S. 1837, p. 61 ; Yarrell, Brit. Fishes, i. p. 49 ; Demid. Voy. Russ. mend. iii. p. 375 ; Guichen. Explor. Alger. Poiss. p. 39 ; Gunther, Catal. ii. p. 203; Couch, Brit. Fishes, ii. p. 36, pi. lxx. f. 21). Some of the authors have personally examined specimens ; others have copied their descriptions from previous writers; but all coincide in the statement that it has not been taken upwards of 4 inches in length. I do not propose giving a detailed account of the species, as such may be found in Cuv. & Val. To what is there recorded I will, however, add that it has ten csecal appendages, and that the number of spined plates along the bases of the dorsal fins is from 25 to 26 on either side, a not uncommon number in the species of this genus. At 5| inches in length the various spinate projections on the head, shoulder, and along the bases of the dorsal fins become more blunted, the colours on the body are not so vivid, while the oval black blotch with blue spots on the inner side of the pectoral fin is more decidedly blue, covered with white spots. If an example, coloured as in T. hirundo, of the same size is placed alongside, scarcely any differences are perceptible; the number of spinate elevations along the bases of the dorsal fins, of the fin-rays, of the rows of scales, and the proportions of the various parts of the body are the same. 1 Yarrell gave a figure of this fish in his second edition from a French drawing. |