Taxonomy and distribution. Goode, G. B. 1882.5; Regan, C. T. 1909.13.

Xiphias (Swordfish). Natural history notes, miscellaneous accounts, descriptions, occurrences. Bureau, L. 1895.1; Cheeseman. T. F. 1876.1; Friedel, E. 1880.3; Holder, C. F. 1876.1; Koelpin, A. B. 1770.1, Add. 1775.1; Knox, F. J. 1870.1; Lanman, C. 1881.1; Münter, J. A. 1876.1; Schnee, S. 1903.3; Sprenger, W. 1900.8.

Swordfish fisheries. Osburn, R. C. 1912.7; Anon. 311. United States. Clark, A. H. 1886.1; Goode, G. B. 1887.2; Italy. Mazzullo, L. 1906.1; ★Mercadante, L., Jannaci, F. & Adorno, M. 1906.1; Brydone, P. Add. 1806.1: Ray, J. Pre-Linn. 1673.1; Silos, G. Pre-Linn. 1683.1.

Pre-Linnaan refs. to the Swordfish. Hannæus, G. 1690.1; Hanow, M. 1737.1; Larren, J. 1707.1; Warren, G. 1667.1. For swordfishes attacking vessels, and fighting whales, see under Predatory fishes. Family Luvaridæ

Classification. Regan, C. T. 1909.13. Luvarus (Ausonia). Natural history and occurrence. Collenette, A. 1904.1; Holder, C. F. 1901.1. At Falmouth."

FAMILY PLEURONECTIDE Used in the inclusive sense, equivalent to the suborder Heterosomata, including the Pleuronectidæ and Soleida, and the numerous other forms recently elevated to family rank. This arrangement is adopted by us as a matter of convenience in citation rather than as any expression of taxonomic relationships.

As articles on the Pleuronectidæ are, in nearly every case, inclusive in their treatment, the citations under the various sub-divisions below will be found to overlap each other greatly as to actual subject matter.

Summary of literature on Dab, Sole, and Turbot. Hoek, P. 1903.1.

Summaries of literature on the Plaice. Duncker, G. 1895.1,.2. 1896.1; Herdman, W.. Scott, A., Johnstone, J. & Cole, F. 1902.1; ★Hoek, P. 1903.1.

Detailed descriptions of the various species. Fries. B., Eckstrom, C. & Sundevall, C. 1836.1, (English trans.) 1893.1; Krøyer, H. N. 1838.1; Day, F. 1880.2; Günther, A. 1859.1.

Briefer diagnoses of the species. Möbius, K. & Heineke, F. 1883.1.

NATURAL HISTORY

Chiefly comprehensive accounts, including in some cases short references to subjects treated in detail in the sections below. Baldwin, A. H. 1863.1, 1879.1; Cunningham, J. T. 1894.1; Fulton, T. W. 1905.3; Lönnberg, A. J. 1894.6; ★Redeke, H. C. Anon. 449; Cockerell, T. D.

Add. 1890.1.

Arnoglossus laterna and thori. Holt, E. W. Add. 1892.1, 1897.2.

Family Coryphænidæ

Delage,

Hippoglossus vulgaris (Halibut). Goode, G. B. 1885.2; ★Thompson, W. F. 1915.1; Ehrenbaum, E. Add. 1914.4; Holt, E. W. Add. 1892.4.

Pleuronectes (Glyptocephalus) cynoglossus (Witch). On coast of North America. Goode, G. B. & Bean, T. H. 1878.1.

Pleuronectes filesus (Flounder). Ascroft, R. L. 1900.2; Braun, M. G. 1880.1; Collin. J. 1876.1; Ehrenbaum, E. 1911.6; Herdman, W. A., Scott, A. & Johnstone, J. 1890.1; Sandman, J. A. 1906.1,.4.

Pleuronectes limanda (Dab). Petersen, C. G. 1893.3.

Pleuronectes (Glyptocephalus) microcephalus (Lemon Dab). Holt, E. W. Add. 1893.4.

1871.1; Lennier, G. Add. 1895.1.

Oreosoma (A genus founded on young of a fish allied to Cyttus). Taxonomy and relationships. Boulenger, G. A. 1903.16; Vaillant, L. L. 1893.2.

Family Amphistidæ

For Amphistium paradoxum from the Upper Eocene, 86e Woodward, A. S. 1889.2 (vol. 4, pp. 434, 435).

Pleuronectes platessa (Plaice). Apstein, C. 1894.1-1905.1; Brüssow, 1879.1; Cole, F. J. & Johnstone, J. Cunningham, J. T. 1895.2..3; Faber, F. 1828.2; Garstang, W. 1905.4, .6, 1909.1; Johansen, A. C. 1905.1, 1909.1, 1910.1, 1912.1; Malard-Duméril, 1898.1; Gilson, G. Add. 1910.1; Hannemann, B. J. Pre-Linn. 1698.1. Putnam's flat fish, a smooth Plaice. Bean, T. H. 1879.12. Vitality of trawl-caught plaice. Borley, J. O. 1909.2.

Rhombus maximus (Turbot). Day, F. 1880.9; LeGoode, G. B. 1880.19;

Records of Occurrence

of Ambicolorate Specimens Chiefly the flounder, plaice, sole, and turbot; and including partially ambicolored piebald" specimens. Bos. J. R. 1886.1; Elmhirst, R. 1911.1; Filhol, H. 1889.1; Johnstone, J. 1909.1; Nicols, A. 1873.1; Pouchet, G. 1892.1; Ritchie, J. 1908.1; Rodd, E. H. 1862.1; Sacchi, M. 1898.1;

E. 1888.1;

Schleep, B. C. 1829.1; Toni, Trois, E. F. 1908.1, 1909.2. - No change in coloration after extirpation of eyes. Buijtendijk, F. J. J. 1911.1. Platessa oblonga with both sides equally colored. Storer, D. H. 1844.10, 1855.1.

Cases of inversion of coloration, i. e., absence of pigmentation on ocular side and appearance of color below. Noury, E. 1909.1; Sacchi, M. 1899.1,.2. -Engyophrys, normally pigmented on blind side. Jordan, D. S. & Bollman, C. H. 1890.1. Theories of causation

Ambicoloration caused by abnormal movements in swimming. Giard, A. 1892.3. - This view contradicted by aquarium experiments of Cuénot, L. 1905.1, 1906.1; and Cunningham, J. T. 1895.1.

Ambicoloration in flatfishes a case of atavism. Kent, W. S. 1873.3. Contradiction of Kent's theory. Suggestion of crossing of normal and reversed specimens as cause of ambicoloration. Romanes, G. J. 1873.1.

Experiments on action of light on the under side of flatfishes. Cunningham, J. T. 1891.3, 1893.1,.10; Cunningham, J. T. & MacMunn, C. A. 1893.1. periments on flatfishes living on slaty bottom. Cunningham, J. T. 1895.1.

Ex

Theories deduced from the above and other experiments with light. Ambicoloration

due (at least in part) to the penetration of light through shallow water to the parts of the fish not in contact with the hard bottom. Cunningham, J. T. 1894.1; Hussakof, L. 1914.3. Ambicoloration probably due to influence of sympathetic nervous system as well as action of light. McIntosh, W. C. 1902.2,.3.

"The eggs of the Pleuronectidæ, like those of the Gadoids, are pelagic or floating, and the species begin life with a denatant drift in the current from deep to shallow water.' Meek (A. 1916.1, p. 262).

This subject has been studied chiefly by means of the results of fishery investigations. For detailed reports and statistics, see the Reports cited below under Migrations. See also under Fisheries.

Descriptions of eggs of various Pleuronectida. Cunningham, J. T. 1888.1; Holt, E. W. 1891.5, 1893.4. Plaice eggs. McIntosh, W. C. & Prince, E. E. 1890.1.

Plate of larval forms. Hoek, P. 1903.1. Spawning areas (chiefly North Sea and coasts of Ireland and Scotland). Meek, A. 1916.1.

General papers on the eggs and larva of Pleuronectida, including their distribution, quantity, development, etc. Kyle, H. M. 1900.7; McIntosh, W. C. 1892.2, 1894.2, 1895.1; ★Petersen, C. G. 1904.2, .4, 1906.2, 1909.2. - Zeugopterus punctatus. Cunningham, J. T. 1893.11. Rhomboidichthys mancus. Facciolà, L. 1887.3. - Pleuronectes cynoglossus. Holt, E. W. & Byrne, L. W. 1903.2. Arnoglossus and Hippoglossus. Williamson, H. C. 1911.2,.4.

Papers treatApstein, C.

Post-larval Stages Chiefly metamorphosis. ing in detail of this stage. 1894.1, 1897.1, 1905.1; Kyle, H. M. 1898.1; McIntosh, W. C. 1888.3, 1889.2, 1896.4; Schmidt, E. J. 1904.2; Williamson, H. C. 1904.1.

Natural history and rate of growth of young plaice after metamorphosis is complete. Cunningham, J. T. 1896.1. Recent detailed account. Fulton, T. W. 1902.3.

Asymmetry of flatfishes

References to Asymmetry will also be found in many of the other articles cited in this section, particularly those under Ambicoloration, Rotation of Eye, and Post-larval stages.

First correct explanation of the asymmetry of the Pleuronectida. ★Traquair, R. H. 1865.1, 1865.2.

Nature and development of the asymmetrical condition, structural changes, etc. Autenrieth, J. H. 1800.1; Beneden, P. J. 1853.3; Crichton-Browne, J. 1907.; ★Cunningham, J. T. 1896.1; ★Duncker,

G. 1900.2; Fullarton, J. H. 1891.1; Fulton, T. W. 1902.3; Malm, A. W. 1854.1, 1868.1, 1880.1; Marshall, W. A. 1885.1; Masterman, A. T. 1910.1, 1912.1; Pfeffer, G. J. 1886.1; Reichert, C. B. 1873.1; Sacchi, M. 1893.1, 1894.1; Steenstrup, J. J. 1863.1, 1864.3-1865.1, 1866.2; Steiner, J. 1886.1,.4; Thomson, C. W. 1865.1; Wright, E. P. 1878.1. Structure of the optic chiasma in asymmetrical fishes. Mayhoff, H. 1912.1; ★Parker, G. H. 1903.2; Williams, S. R. 1902.1.

Rotation of eyes

The change of the eyes of the larval flatfish during growth or metamorphosis from a bilateral condition to approximation on one side of the head, with the accompanying changes in the optic tract, cranial skeleton, etc.

As first enunciated by Traquair, the whole of the cranium in the region of the orbit has rotated on its longitudinal axis.

Various papers. ★Agassiz, A. 1876.1, 1877.2, 1878.1 (ii), 1879.3; Behr, A. 1899.1; ★Ehrenbaum, E. 1897.1 (i); ★Facciolà, L. 1885.2, 1887.3, 1901.1; Harting, P. 1866.2, 1878.5; Hawkes, A. J. 1907.1; Mayhoff, H. 1914.1; Nishikawa, T. 1897.1; ★Parker, G. H. 1903.2; Pfeffer, G. J. 1894.2; Provazek, F. 1900.1; Schiødte, J. M. 1868.1, 1877.1; Thilo, O. 1902.3,.4. 1908.1; ★Williams, S. R. 1901.1, 1902.1; Wright, E. P. 1879.1; Anon. 359; Hanow, M. Pre-Linn. 1737.1.

Views of Steenstrup who believed that one eye passed through the substance of the head. Steenstrup, J. J. 1866.2, 1876.1.

Records of cases of arrested rotation of the eyes, teratological conditions resulting in complete or partial retention of bilateral symmetry, often accompanied by other minor abnormalities in coloration, etc. Filhol, H. 1889.1; Giard, A. 1892.3;

Holt, E. W. 1893.2; Johnstone, J. 1909.1; Ninni, E. 1906.1; Ritchie, J. 1908.1; Sacchi, M. 1898.1; Schleep, B. C. 1829.2; Storer, D. H. 1844.10.

Teratological specimens showing a reversal of the eye position, i. e., the occurrence of both eyes on the opposite side of that normal for the species. Specimens of Turbot (Psetta maxima). Cunningham, J. T. 1907.1. -Flounder. Traquair, R. H. 1900.3.

DISTRIBUTION

Predominantly Northern

For distribution of eggs and larra, see also the articles cited above under Eggs and Larvæ.

For areal and bathymetric distribution, see particularly Cunningham, J. T. 1896.1; Day, F. 1880.2; Fulton, T. W. 1893.2; ★Hoek, P. 1903.1 (Plaice, Sole, and Dab); Holt, E. W. 1893.1; Johansen, A. C. 1905.1; Meek, A. 1916.1.

Bathymetric distribution. Herdman, W. & Dawson, R. 1902.1; Schiemenz, P. 1902.1.

Distribution in Arctic waters. Alaska; Halibut. Bean, T. H. 1879.10. Murman Coast and White Sea. Knipovich, N. M. 1901.1, 1902.1. - Behring Sea, Alaska and Sea of Okhotsk, and White Sea; Plaice. Smitt, F. A. 1893.1.

Baltic Sea. Möbius, K. & Heincke, F. 1883.1. Plaice in Baltic. Duncker, G. 1904.2; Krüger, Albert. 1903.1, 1904.1; Mortensen, O. T. J. 1895.1; Reibisch, J. 1904.1, 1907.1, 1911.1. Effect of low specific gravity on plaice distribution in Baltic. Hensen, V. A. 1884.1; Petersen, C. G. 1894.1. Dab. Schiemenz, P. 1902.1.

Distribution on coast of Finland.
Plaice. Fischer, J. 1875.1.
Malmgren, A. J. 1863.1.
Sandman, J. A. 1906.1.

Dab.

- Halibut.

AND MARKING EXPERIMENTS The majority of articles on these subjects have been published in 1902 and the following years in the Reports listed below: Rept. Lancashire Sea-Fisheries Lab., Liverpool; Rept. Fishery Board for Scotland, London; Mitt. Deutsch. Seefischereivereins, and the publications of the Commission Wissenschaft. Untersuch. Deutsch. Meere, Kiel.

Although the migratory movements of the various genera and species differ slightly owing to external influences, such as temperature, we may in the main use the following summary of

The migratory habits of the flatfishes have been chiefly studied by means of marking experiments on plaice in the North and Irish and Baltic Seas. For a bibliography on plaice marking experiments, see Atkinson, G. T. 1912.1.

Marks in use in marking experiments. Heincke, F. & Bolau, H. 1906.1.

For investigations on the migration of Pleuronectidae in order to determine questions of Size, Growth. Food, and Temperature effects, see the larger papers cited in this section and also these subjects in the Morphological Section.

General papers on the migrations of flatfishes. Cole, F. S. & Johnstone, J. 1901.1; Meek, A. 1916.1. See also

J. T. Jenkins The Sea Fisheries." London, 1920, 299 p. figs., and various shorter papers on the results of the Northumberland investigations by Meek, (A. 1905.1, 1909.2, 1913.1, 1914.2,.3, 1915.3).

For detailed reports on localities, seasons, etc. of mature spawning migrations of Pleuronectida, see particularly the Reports of the Dove Marine Laboratory, Cullercoats.

Seasonal migration of Pleuronectida (in-shore in summer and into deeper water in winter, until maturity is reached). -Flounders marked in Elbe in autumn recaptured in Elbe. Ehrenbaum, E. 1907.3.

Young plaice appearing in the mouths of rivers. Feddersen, A. 1879.1; Hoek, P. 1888.1; Seeley, H. G. 1886.1. Where are plaice in winter?" Petersen, C. G. J. 1893.2. Marked soles in the Zuyder Zee. Tendency to southwest migration. Redeke, H. C. 1905.1, 1911.1. Flounders marked in Feb. and May on Bornholm grounds in Baltic, recaptured near coast the following summer. Strodtman, S. 1906.1.

Effects of seasonal migrations analyzed - for Forth school. Thompson, D. W. 1914.2; Fulton, T. W. ("Goldseeker investigations) 1913.2. for Northumber

land school. Meek, A. 1916.1, p. 271.

Increase in growth of Plaice as result of transplantation to richer feeding grounds. Experiments in North Sea, 1896-1908. Borley, J. (Summary) 1912.2; Garstang, W. 1905.1; Petersen, C. 1896.4, 1897.1. Migratory habits peculiar to certain flatfishes. Plaice and Dab are usually found together. Plaice begins to spawn earlier in year than Dab. Cunningham, J. T. Add. 1898.1. - Flounder lives in estuaries and rivers, only descending to the

Marking experiments in various localities. North sea. Atkinson, G. T. 1909.1– 1912.1; Bolau, C. C. 1905.1; Ehrenbaum, E. 1907.3; Lee, R. M. & Atkinson, G. T. 1912.1; Reichard, A. C. 1909.1, 1910.1, 1915.1,.2. - Irish Sea. Farran, G. P. 1909.1; Johnstone, J. 1905.3,.5, 1911.1, 1912.2. Baltic Sea. Johansen, A. C. 1905.1, 1909.1, 1910.1, 1912.1. Iceland. Sæmundsson, B. 1913.1; Schmidt, E. J. 1907.1.

PHYLOGENY

Evolution and origin of species of flatfishes. Bateson, W. 1894.1; ★Cunningham, J. T. 1892.1, 1895.6, Add. 1898.1; Giard, A. 1892.1; Regan, C. T. 1910.6; Thilo, O. 1899.2, 1903.3.

TAXONOMY

Family Pleuronectidæ

See also general papers on this subject under Taxonomy in the Morphological Section.

Systematic works. Andrews, W. 1849.5; Boulenger, G. A. 1901.15; ★Cunningham, J. T. 1893.1, 1895.6, Add. 1894.1; Kyle, H. M. 1900.1.

For group and generic names given to larval forms, see Jordan, D. S. & Goss, D. K. 1889.1.

Geographical variations. Cligny, A. 1905.4. India. Alcock, A. W. (Bay of Bengal) 1889.2; Jenkins, J. T. 1910.2. East Indies. Bleeker, P. 1851.15, 1852.12, 1862.1..9. Africa. Boulenger, G. A. 1902.19. Sicily. Facciolà, L. 1885.2. North America. Gill, T. N. 1865.14, .15, 1889.1; Lockington, W. N. (California) 1879.12. - Great Britain. Günther. A. C. 1890.1. Review, America