On the Orthography of the Genus Chroïcocephalus.—In 1836, Mr. T.C. Eyton (Hist. Rarer Brit. Birds, p. 57) proposed "the name Chroicocephalus for a new subgenus under Larus, Linn., for the reception of such gulls as have the tarsi slender, thighs considerably denuded, hind toe very small, head only, or head and upper part of neck, dark-coloured in the summer state of plumage;" and in a footnote he added that the name was "derived from two Greek words, χροικος, coloured, and κεφαλη, head; signifying that the birds classed under that name have coloured heads."
It is curious to trace the uncertainty that has arisen in the minds of some of the most learned ornithologists from this misprint of the first Greek word here cited. In 1839, Dr. William Jameson (Journ. Asiat. Soc, viii., 241), in a "report on the Museum of the Asiatic Society," mentions "Larus kroikocephalus" as referable to "the genus kroikocephalus of Eton" [sic]; and he remarks: "The name we have adopted is one which we have proposed to the Wernerian Society, being the generic one of Eton [sic] reduced to trivial value." The late Dr. T.C. Jerdon ('Birds of India,' 1864, p. 831) was so far misled by this violation of the laws of language and of nomenclature as to adopt "kroikocephalus" as a generic name. In 1841, H.E. Strickland (Ann. Nat. Hist., vii., 40) in a "commentary on Mr. G.R.Gray's 'Genera of Birds,'" simply remarks: "Chroicocephalus should be written Chrœcocephalus," thus regarding the first two vowels as forming a diphthong. His untenable correction has been extensively adopted. In 1842, Professor Agassiz ('Nomenclator Zoologicus') was so confused by Eyton 's Greek spelling as to derive Chroicocephalus from χροιά = colour, by a process comprehensible only to himself. In 1851, Dr. Reichenbach, in a "Systema Avium" prefixed to a copy of his "Handbuch der Speciellen Ornithologie," gives as a division of his family Larinæ the genus "Chroiocephalus, Eyton," as if misled by Agassiz' false etymon. In 1871, Messrs. Sclater and Salvin, in a " revision of the neo-tropical Larida " (Proc. Zool. Soc, p. 576), group the hooded gulls under the genus Chroocephalus, with the following explanatory foot-note: " Usually written Chroicocephalus, or Chrœcocephalus, as amended by Strickland. But if, as we suppose, the derivation is from χρώς, χροός, colour, this [Chroocephalus] is the proper orthography." But the need for all this conjecture vanishes when it is known that there exists an adjective, χρωικος, meaning coloured. The larger lexicons, such as Stephanus' great ' Thesaurus Linguæ Græcæ' (9 vols., folio, Paris, 1865), gives the word as having been used by Justin Martyr about the year 150 a.d.; the exact reference to Otto's edition is vol. hi., part I., p. 204 B, and the quotation in full is έν τοίς χρωικοις το χρώμα = "in coloured things there is colour." Nothing further is necessary to prove that Eyton's original spelling of his name Chroïcocephalus
