Chapter XV: Isthmus Barriers Separating Fish Faunas

The Isthmus of Suez.--The Fish Fauna of Japan.--Fresh-water Faunas
of Japan.--Faunal Areas of Marine Fishes of Japan.--Resemblance
of Japanese and Mediterranean Fish Faunas.--Significance of
Resemblances.--Differences between Japanese and Mediterranean Fish
Faunas.--Source of Faunal Resemblances.--Effects of Direction of
Shore Lines.--Numbers of Genera in Different Faunas.--Significance
of Rare Forms.--Distribution of Shore-fishes.--Extension
of Indian Fauna.--The Isthmus of Suez as a Barrier to
Distribution.--Geological Evidences of Submergence of Isthmus of
Suez.--The Cape of Good Hope as a Barrier to Fishes.--Relations of
Japan to the Mediterranean Explained by Present Conditions.--The
Isthmus of Panama as a Barrier to Distribution.--Unlikeness
of Species on the Shores of the Isthmus of Panama.--Views of
Dr. Günther on the Isthmus of Panama.--Catalogue of Fishes of
Panama.--Conclusions of Evermann & Jenkins.--Conclusions of Dr.
Hill.--Final Hypothesis as to Panama. 255

CHAPTER XVI.

DISPERSION OF FRESH-WATER FISHES.

The Dispersion of Fishes.--The Problem of Oatka
Creek.--Generalizations as to Dispersion.--Questions Raised by
Agassiz.--Conclusions of Cope.--Questions Raised by Cope.--Views
of Günther.--Fresh-water Fishes of North America.--Characters of
Species.--Meaning of Species.--Special Creation Impossible.--Origin
of American Species of Fishes. 282

CHAPTER XVII.

DISPERSION OF FRESH-WATER FISHES. (_Continued._)

Barriers to Dispersion of Fresh-water Fishes: Local
Barriers.--Favorable Waters Have Most Species.--Watersheds.--How
Fishes Cross Watersheds.--The Suletind.--The
Cassiquiare.--Two-Ocean Pass.--Mountain Chains.--Upland
Fishes.--Lowland Fishes.--Cuban Fishes.--Swampy Watersheds.--The
Great Basin of Utah.--Arctic Species in Lakes.--Causes of
Dispersion still in Operation. 297

CHAPTER XVIII.

FISHES AS FOOD FOR MAN.

The Flesh of Fishes.--Relative Rank of Food-fishes.--Abundance
of Food-fishes.--Variety of Tropical Fishes.--Economic
Fisheries.--Angling. 320

CHAPTER XIX.

DISEASES OF FISHES.

Contagious Diseases: Crustacean Parasites.--Myxosporidia or
Parasitic Protozoa.--Parasitic Worms: Trematodes, Cestodes.--The
Worm of the Yellowstone.--The Heart Lake Tape-worm.--Thorn-head
Worms.--Nematodes.--Parasitic Fungi.--Earthquakes.--Mortality of
Filefish. 340

CHAPTER XX.

THE MYTHOLOGY OF FISHES.

The Mermaid.--The Monkfish.--The Bishop-fish.--The Sea-serpent. 359

CHAPTER XXI.

THE CLASSIFICATION OF FISHES.

Taxonomy.--Defects in Taxonomy.--Analogy and Homology.--Coues
on Classification.--Species as Twigs of a Genealogical
Tree.--Nomenclature.--The Conception of Genus and
Species.--The Trunkfishes.--Trinomial Nomenclature.--Meaning
of Species.--Generalization and Specialization.--High and Low
Forms.--The Problem of the Highest Fishes. 367

CHAPTER XXII.

THE HISTORY OF ICHTHYOLOGY.

Aristotle.--Rondelet.--Marcgraf.--Osbeck.--Artedi.--Linnæus.--
Forskål.--Risso.--Bloch.--Lacépède.--Cuvier.--Valenciennes.--
Agassiz.--Bonaparte.--Günther.--Boulenger.--Le Sueur.--Müller.--
Gill.--Cope.--Lütken.--Steindachner.--Vaillant.--Bleeker.--
Schlegel.--Poey.--Day.--Baird.--Garman.--Gilbert.--Evermann.--
Eigenmann.--Zittel.--Traquair.--Woodward.--Dean.--Eastman.--Hay.--
Gegenbaur.--Balfour.--Parker.--Dollo. 387

CHAPTER XXIII.

THE COLLECTION OF FISHES.

How to Secure Fishes.--How to Preserve Fishes.--Value of
Formalin.--Records of Fishes.--Eternal Vigilance. 429

CHAPTER XXIV.

THE EVOLUTION OF FISHES.

The Geological Distribution of Fishes.--The Earliest
Sharks.--Devonian Fishes.--Carboniferous Fishes.--Mesozoic
Fishes.--Tertiary Fishes.--Factors of Extinction.--Fossilization
of a Fish.--The Earliest Fishes.--The Cyclostomes.--The
Ostracophores.--The Arthrodires.--The Sharks.--Origin of the
Shark.--The Chimæras.--The Dipnoans.--The Crossopterygians.--The
Actinopteri.--The Bony Fishes. 435

CHAPTER XXV.

THE PROTOCHORDATA.

The Chordate Animals.--The Protochordates.--Other Terms Used
in Classification.--The Enteropneusta.--Classification of
Enteropneusta.--Family Harrimaniidæ.--Balanoglossidæ.--Low
Organization of Harrimaniidæ. 460

CHAPTER XXVI.

THE TUNICATES, OR ASCIDIANS.

Structure of Tunicates.--Development of
Tunicates.--Reproduction of Tunicates.--Habits of
Tunicates.--Larvacea.--Ascidiacea.--Thaliacea.--Origin of
Tunicates.--Degeneration of Tunicates. 467

CHAPTER XXVII.

THE LEPTOCARDII, OR LANCELETS.

The Lancelet.--Habits of Lancelets.--Species of Lancelets.--Origin
of Lancelets. 482

CHAPTER XXVIII.

THE CYCLOSTOMES, OR LAMPREYS.

The Lampreys.--Structure of the Lamprey.--Supposed Extinct
Cyclostomes.--Conodontes.--Orders of Cyclostomes.--The
Hyperotreta, or Hagfishes.--The Hyperoartia, or Lampreys.--Food
of Lampreys.--Metamorphosis of Lampreys.--Mischief Done by
Lampreys.--Migration or "Running" of Lampreys.--Requisite
Conditions for Spawning with Lampreys.--The Spawning Process with
Lampreys.--What Becomes of Lampreys after Spawning? 486

CHAPTER XXIX.

THE CLASS ELASMOBRANCHII, OR SHARK-LIKE FISHES.

The Sharks.--Characters of Elasmobranchs.--Classification
of Elasmobranchs.--Subclasses of Elasmobranchs.--The
Selachii.--Hasse's Classification of Elasmobranchs.--Other
Classifications of Elasmobranchs.--Primitive Sharks.--Order
Pleuropterygii.--Order Acanthodii.--Dean on Acanthodii.--Order
Ichthyotomi. 506