THE ROYAL NATURAL HISTORY ^■•♦l THE ROYAL NATURAL HISTORY EDITED BY RICHARD LYDEKKER, B.A., F.R.S., Etc. WITH PREFACE BY P. L. SCLATER, M.A., Ph.D., F.R.S., SECRETARY OF THE ZOOLOGICAL SOCIETY OF LONDON ILLUSTRATED WITH Seventy-two Coloured Plates and Sixteen Hundred Engravings W. KUMERT, F. SPECHT, P. J. SMIT, G. MUTZEL, A. T. ELWES, J. W0L1 GAMBIER BOLTON, F.Z.S.: AND MANY OTHERS VOL. V. LONDON" FREDERICK vVARNE & CO. A N D N E W YORK 1896 [All High In Reserved] an 4S Lcf 1/6" co^x MORRISON AND GIBB. PRINTERS. EDINBURGH CONTENTS REPTILES CHAPTER I. — General Characteristics of the Class Eeptilia. Differences between Reptiles and other Vertebrates — Diversity of Form and Structure— Skeleton — Teeth — Vertebrae — Classification and Distribution, CHAPTER II. — Crocodiles, Dinosaurs, and Flying Dragons, — Orders Crocodilia, Dinosauria, and Ornithosauria. Characteristics of Crocodiles — Their Habits — Existing Crocodiles (Crocodilida?) — Caimans (Caiman) — Alligators (Alligator) — Double-Tusked Alligators (Diplocynodon) — Stumpy Crocodile (Osteolcemus) — True Crocodiles (Crocodilus) — Indian Crocodile — Estuarine Crocodile — Nile Crocodile — Siam Crocodile — Sharp - Nosed Crocodile - — Orinoco Crocodile — Long-Nosed Crocodile — Schlegel's Garial (Rhynchosuchus) — Garial (Garialis) — Extinct Garial — The Earlier Crocodiles — The Extinct Dinosaurs (Dinosauria) — Flying Dragons, or Pterodactyles (Ornithosauria), ..... 10 CHAPTER III. — Tortoises, Turtles, and Plesiosaurs,- and Sauropterygia. -Orders Chelonia Characteristics of Tortoises and Turtles (Chelonia) — Their Habits and Distribution — The Land-Tortoises and Terrapins (Testudinidca) — Land-Tortoises (Testudo) — Florida Tor- toise— Brazilian Tortoise — Burmese Brown Tortoise — Elegant Tortoise — Giant Tor- toises — Aldabra Tortoise — Mascarene Tortoises — Galapagos Tortoises — Grecian Tortoise — Other Species — Angulated Tortoise — Areolated Tortoise (Homopus) — Hinged Tortoises (Ciuixys) — Spider-Tortoise (Pyxis) — Spinose Land-Terrapin (Geoemyda) — Chaibassa Terrapin (Nicoria) — Hinged Terrapins (Cyclemys) — Box-Tortoises (Cistudo) — Pond-Tortoises (Emys)— Terrapins — Sculptured Terrapin (Clemmys) — Thick-Necked Terrapin (Bellia)— Hamilton's Terrapin (T)amonia) — Soft- Water Terrapin (Malaco- clemmys) —Painted Terrapin (Chrysemys)— Eyed and Chinese Terrapins (Morenia) — vi CONTENTS PAGE Batagurs (Cachuga, etc.) — Big-Headed Tortoise (Platysternidce) — Mud-Terrapins and their Allies (Cinosternidce and Dermatemydidce) — Maw's Terrapin (Dermatemys) — The • Snappers and Alligator - Terrapins (Chelydridce) ■ — Alligator - Terrapin (Chelydra) — Tcmminck's Snapper (Macroclemmys) — The Turtles (Chelonidce)— Green and Hawks- hill Turtles (Chelone) — Loggerhead Turtle (Thalassochelys) — Hahits of Turtles — Tor- toise-Shell— Extinct Turtles — Leathery Turtles (Dermochelyidce) — The Side-Necked Tortoises (Clielyidce and Pelomedusidce) — Mataniata Tortoise (Chelys) — Snake-Necked Tortoises (Hydromedusa) — Australian Long-Necked Tortoises (Chelodina) — Other Genera — Greaved Tortoises (Podocnemis) — Allied Genera — Fly Biver Turtle (Caretto- chelyidce) — Australian Horned Tortoises (Miolaniidce) — Extinct European Genera — Generalised Chelonians (Pleurosternum, etc.) — The Soft-Tortoises (Trionychidce) — Typical Genus (Trionyx) — Granulated Soft-Tortoises (Emyda, etc.) — Habits of the Group — The Plesiosaurs, or Long-Necked Marine Lizards (Order Sauropterygia), . 42 CHAPTEB IV. — Scaled Beptiles — Lizards and Chameleons, — Order Squamata ; Suborders, Lacertilia and Rhiptoglossa. Characteristics of the Order — Skull — Bibs and Vertebra — Other Characters — Special Charac- ters of Lizards (Suborder Lacertilia) — Numbers and Distribution — Habits — The Geckos (Geckonidoz) — Lobe-Footed Gecko (Ptyodactylus) — Turkish Gecko (Hemidactylus) — Fringed Gecko — Wall-Gecko — Habits of the Group — Eyelid Geckos — The Scale-Footed Lizards (Pygopodida?) — The Agamoid Lizards (Agamidai) — Flying-Lizards (Draco) — Oriental Tree-Lizards (Calotes) — Ceylon Horned Lizards (Ceratophora) — Typical Group (Agama) — Armed Agama — Spinose Agama — Bough-Tailed Agama — Australian Frilled Lizard (Chlamydosaurus) — Sail-Tailed Lizard (Lophurus) — Thorny-Tailed Lizards (Uromastix) — Habits — East African Thorny-Tailed Lizards (Aporoscelis)- -Moloch Lizard (Moloch) — The Iguanoid Lizards (Iguanidai) — Anolis Lizards (Anolis) — Allied Genera — Basilisks (Basiliscus) — Bidge-Headed Lizards (Corythophanes) — Stilted Lizards ( Uranis- codon) — The Sea-Lizard (Amblyrhynchus) — Galapagos Land-Lizard (Conolophus) — True Iguanas (Iguana) — Bing- Tailed Iguana (Cyclura) — Extinct Iguanas — Horned Lizards (Phrynosoma) — The Girdled Lizards (Zonuridas) — Girdle-Tailed Lizard (Zonurus) — The Snake-Like Lizards (Anguidw) — Scheltopusiks (Ophisaurus)— Blind-Worm (Anguis) — The Poisonous Lizards (Helodermatidaz) — The Monitors (Varanida?) — Their Habits — The Greaved Lizards (Teiidce) — The Teju (Tupinambis) — The Ameivas (Ameiva) — The Am])hishiena,8(Amphisbamida?) — Handed Amphisbaena (Chirotes) — Typical Amphisbsenas (Amphisbozna) — The True Lizards (Lacertida?) — Pearly Lizard (Lacerta) — Green Lizard — Sand-Lizard — Viviparous Lizard — Wall- Lizard — Keeled Lizards (Algiroides) — Fringe- Toed Lizards (Acanthodactylus) — The Skink Tribe (Scincidce) — Stump-Tailed Lizard (Trachysaurus) — Snake-Eyed Lizards (Ablepharus) — True Skinks (Scincus)— Bronze Lizards (Chalcides) — Other Families (Anelytropidm and Dibamidoz) — The Chamadeons (Suborder Rhiptoglossa) — Their Habits, ....... 104 CHAPTEB V. — Scaled Beptiles, — continued. The Snakes — Suborder Ophidia. Distinctive Characters and Structure — Teeth — Harmless and Poisonous Snakes — Distribution — Habits — The Blind Snakes (Typhlopodidm and Glauconiidw) — The Pythons and Boas (Boidm) — True Pythons (Python) — Their Distribution and Habits — The Various Species — Allied Genera (Loxocemus, Nardoa, etc.) — Tree-Boas (Epicrates) — Dog-Headed Tree- Boa (Corallus) — Keeled Tree-Boas (Enygrus) — Anaconda (Euneces) — True Boas (Boa) — Keel-Scaled Boa (Gasarea) — Sand-Snakes (Eryx)— Allied Genera (Lichanura, etc.)— Extinct Python-Like Snakes (Palasophis)— The Cylinder-Snakes (Ihjsiidce)— Coral Cylinder-Snake (Ili/sia)— Bed Snake (Cylindrophis)—The Shield-Tails (UropeUidce)— The Colubrine Snakes (Colubridm) — Wart-Snakes (A crochor'dus) — Water - Snakes (Tropidonotus)— Binged Snake— Tesselated and Viperine Snakes— Oblique-Eyed Snakes (Helicops)— Pigmy Snakes (Calamaria) — Sling-Snakes (Coronella) — Fierce Snakes (Zamenis)— Horseshoe Snake— Bat-Snake — Bunning Snakes (Ptyas) — Climbing Snakes CONTENTS vil PAGE {Coluber)— Black- Marked Snake — Wood-Snakes (Herpetodryas) — Tree-Snakes (Dend- ■ rophis and Dendrelaphis) — Egg-Eating Snake (Dasypeltis) — Moon-Snakes (Scytale) — Cat- Snake (Tarbophis) — Nocturnal Tree - Snakes (Dipsas) — Back-Fanged Tree -Snakes (Philodryas and Dryophis) — Sharp - Nosed Snakes (Oxybelis) — Oriental Fresh- Water Snakes (Homalopsince) — Coral-Snake (Elaps) — Resplendent Adders (Callophis) — Long- Gland ed Snakes {Adeniophis) — Craits (Bungarus) — Cobras (Naia) — Their Habits — Death - Adders (Pseudechis) — Sea - Snakes {Hydrophiince) — Broad-Tailed Sea - Snakes (Platurus) — Parti-Coloured Sea-Snake (Hydrus) — Black- Banded Sea-Snake (Distira) — The Vipers ( Viperidce) — True Vipers ( Viperince) — Common Viper ( Vipera) — Southern Viper — Long-Nosed Viper — Russell's Viper — Puff- Adder — Horned Vipers (Cerastes) — Desert Saw- Vipers (Echis) — Rattle-Snakes (Crotalince) — Common Rattle-Snake (Cro- talus) — Diamond Rattle-Snake — South American Rattle-Snakes — Habits of Rattle- Snakes — The Bushmaster (Lachesis) — Halys Vipers (Ancistrodon) — Himalayan Halys Siberian Halys — Copper-Head Snake — Water- Viper— Typical Pit-Vipers (Trimere- saurus) — Jararaca — Extinct Groups of Scaled Reptiles — Long-Necked Lizards (Dolichosauria) — Cretaceous Sea-Serpents (Pythonomorpha), .... 174 CHAPTER VI. — The Remaining Groups of Reptiles, — Orders Ichthyopterygia, Rhynchocephalia, and Anomodontia. The Fish- Lizards (Order Ichthyopterygia) — The Beaked Lizards (Order Rhynchocephalia) — The Tuatera (Sphenodon) — Allied Extinct Families (HomceosauridcE and Ehynchosatiridce) — Oldest Types (Proterosaurus, etc.) — The Anomodonts, or Mammal- Like Reptiles (Order Anomodontia) — Dicynodonts and Theriodonts, ...... 250 AMPHIBIANS CHAPTER I.— General Characteristics of the Class Amphibia — Frogs and Toads — Order Ecaudata. Distinction between Amphibians and Reptiles — Skin of Amphibians — Skeleton — Soft Parts — Development — Distribution — Habits — Characteristics of Frogs and Toads — The Typical Frogs (Ranida}) — Water-Frogs (Rana)— European Frogs — Bull-Frogs — Oxy- glossus — Flying Frogs (Rhacophorus) — Solid- Chested Tree-Frogs (Dendrobatidce) — The Narrow-Mouthed Frogs (Engystomatidce) — Sharp-Nosed Frog (Ceratobatrachidw)— The Southern Frogs (Leptodactylidaz) — Horned Frogs (Ceratophrys) — Leaf-Frogs (Hylodes) —Piping-Frogs (Leptodactylus) — The Toads (Bufonidw)— True Toads (Bufo)— Green Toad — Natterjack Toad — Sharp-Nosed Toad (Rhinophrynus) — The Overlapping- Chested Tree-Frogs (Hylidce) — Grasshopper-Frog (Acris) — Typical Tree-Frogs (Hyla) — Their Nesting - Habits — Pouched Tree-Frogs (Nototrema) — Pouched Tree-Frogs (Pelobatidoe)— Brown Toad-Frog (Pelobates)— Other Genera (Pelodijtes, etc.) — Allied Extinct Frogs (Palceobatrachidai) — The Disc-Tongued Frogs (Discoglossidce) — Fire- Bellied Frog (Bombinator)— Midwife-Frogs (Alytes)— Other Families (A mphignathodon- tidce and Hemiphractidre)— The Tongueless Frogs (Xenopodidce and Pipidai) — Spur-Toed Frogs (Xenopus) — Surinam Water- Toad (Pipa), ...... 257 CHAPTER II. — Newts, Salamanders, and Cosciltans, — Orders Caudata and Apoda. Distinctive Characters of the Caudata — Their Distribution and Habits — The Salamander Tribe (Salamandridce)— Typical Salamanders (Salamandra) — Alpine Salamander — Spanish Salamander (Chioglossa)— Newts (Molge)— Crested Newt— Marbled Newt- Alpine Newt — Common Newt— Webbed Newt — Other Species — Habits of Newts — Spectacled Salamander (Salamandrina) — Other Genera (Tylotriton and Pachytriton) — Axolotls (Ambly stoma) — Other Genera — The Fish-Like Salamanders (Amphiumidce) — Giant Salamander (Megalobatrachus) — Hell-Bender (Cryptobranchus) — Three-Toed viii CONTENTS PAGB Salamander (Amphiuma) — The Gilled Salamanders (Proteidce)— 01m (Proteus) — Furrowed Salamander (Necturus) — Two-Legged Salamanders (Sirenidce)— The Coecil- ians, or Worm-Like Amphibians (Order Apoda), ...... 289 CHAPTER III. — The Primeval Salamanders, — Order Labyrinthodontia. Characters and Distribution of the Group — The Leading Families and Genera, . ,311 FISHES CHAPTER I. — General Characteristics of the Class Pisces. Classification — External Skeleton — Internal Skeleton — Teeth — Coloration — Soft Parts- Reproduction — Tenacity of Life — Distribution, , . . . ... 314 CHAPTER II. — Lung-Fishes and Chim^eroids, — Subclasses Dipnoi and Holocephali. Existing Lung-Fishes (Lepidosirenidce) — Australian Lung-Fish (Ceratodus) — South American Mud-Fish (Lepidosiren) — African M\\d-Fish(Protopterus) — Extinct Lung-Fishes — Berry- Bone Fishes (Order Arthrodira) — The Chimseroids (Subclass Holocephali), . . 325 CHAPTER III. — The Bony Fishes and Ganoids,— Subclass Teleostomi. Classification — Fan-Finned Group (Order Actinopterygii) — Spine-Finned Fishes (Suborder Acanthopterygii) — The Perch Tribe (Percidce) — True Perches (Perca) — Pike-Perches (Lucioperca) — Danubian Perches (Aspro) — Ruffes (Acerina) — Centrarchidce — Bass and Sea- Perches (Serranidce)- South American Perch and Bass (Percichthys and Morone)— Sea-Perch (Centropristes, Serranus, etc.) — Stone-Bass (Polyprion) — Oriental and African Perches (Lates and Psammoperca) — Scaly-Finned Fishes (Ch(ttodontid(e)—Chcetodon — Chelmon — Heniochus — Holacanthus — Red Mullets (Mullidce) — Sea-Breams (Sparidce) — Cantharus — Haplodactylus — Sargus- — Gilt-Heads (Chrysophrys) — Knife-Jawed Fishes (Hoplognathidve) — Thick-Rayed Fishes (Girrhitidce) — Cirrhitichthys — Chilodactylus — Scorpaenoids (Scorpamidce) — Allied Families — Berycoids, or Slime-Heads (Berychidce) — Gurtidce, and Polynemidce — Scisenoids (Scicenidce) — Drum (Pogonias) — Umbrines (Umbrina) — Meagres (Scicena) — Sword -Fishes (Xiphiidoe)— Scabbard-Fishes and Hair- Tails (Trichiuridce) — Scabbard-Fish (Lepidopus) — Hair-Tails (Trichiurus) — Barracudas (Thyrsites) — Extinct Forms — Surgeons (A cronuridcc) — Horse-Mackerels (Carangidce) — Typical Group (Caranx) — Pilot-Fish (Naucrates) — Sea-Bats (Platax) — Dories (Cyttidce) — Stromateids and Coryphaenas (Stromateida; and Coryphcenidce) — Coryphcena — Sun-Fish (Lampris) — Nomeeids (Nomceidce) — Mackerels (Scomberidce) — Thunnies (Thynnus) — Sucking-Fishes (Echeneis) — Star-Gazers and Weavers (Trachinida?) — Uranoscopus — Trachinus — Tile-Fish (Lopholatilus) — Other Groups — Soft-Spines and Frog-Fishes (Malacanthidce and Batrachidce) — Batrachus — Angler-Fish and their Allies (Lophiidce) — Anglers (Lophius) — Tentacle-Fish (Antennarius) — Bull-Heads and Gurnards (Cot- tidce — Bull-Heads (Cottus) — Gurnards (Trigla) — Beaked Gurnards (Peristethus) — Flying Gurnards (Da'ctylopterus) — Dragon-Fishes (Pegasus) — Lump-Suckers (Cyclopteridce) — Gobies and Mud-Skippers (Gobiidai) — Gobnis — Periophthalmus— Band-Fishes (Cepolidw) — Hairy-Backs (Trichonotidai) — Chiridas — Blennies (Blenniidce) — Viviparous Blennies (Zoarces) — Wolf -Fishes (Anarrhichas) — Oblique-Spin ed Blenny (Acanthoclinidce) — Spiny Eels (Rhijnchobdellida?) — Oil-Fish (Comephorus) — Barracuda-Pikes (Sphyrcenidce) — Sand-Smelts (Atherinidm) — Square-Tail (Tetragonurus) — Grey Mullets (Mugilidre) — Gar-Pike and Flying-Fish (Scombresocida}) — Gar- Pike (Belone)— rFlying-Fish (Exocoztus) — Sticklebacks (Gastrosteida?) — Flute-Mouths (Aulostomatidce) — Trumpet-Fish (Cen- triscidai) — Sucker-Fishes (Gobioesocidw) — Serpent-Heads (Ophioceplialidai) — Labyrinth- Gilled Fishes (Anabantidas and Luciocephalidm) — Climbing- Perch (Anabas) — Paradise- Fish (Polyacanthus) — Gurami (Osphrornenus) — Fighting-Fish (Betta) — Unicorn-Fish CONTENTS ix PAGE (Lophotidas) — Ribbon-Fish (Trachyptcridce)— Thornbacks (Notacanthidce) — Pomacentridce — Wrasses (Labridai) — -True Wrasses (Labrus) — Parrot- Wrasses (Scarus) — Viviparous Wrasses (Diatrematidce) — Chromids (Chromididaz) — Tuft-Gilled Fishes (Suborder Lopho- branchii) — Mailed Tube-Mouths (Solenostomatidce) — Pipe-Fishes and Sea-Horses (Syn- gnathidce) — Comb-Gilled Group (Suborder Plectognathi) — File-Fishes and Coffer- Fishes (Balistidce) — Globe-Fishes and Sun-Fishes (Diodontidce) — Soft-Finned Fishes (Suborder Anacanthini) — Lycodidce — The Cod Tribe (Gadidce) — True Cod (Gadus) — Haddock — Other Species-— Hakes (Merluccius) — Burbot (Lota) — Ling and Rockling (Molva) — Sand-Eels and their Allies (Ophidiidce) — Cave-Fish (Lucifuga) — Snake- Fishes (Ophidium) — Parasitic Fish (Fierasfer) — Sand-Eels (Ammodytes) — Conyrodus — The Long- Tails (Macruridce) — Fiat-Fishes (Pleuronectida?) — Psettodes — Holibut (Hippo- glossus) — Turbot, etc. (Rhombus) — Plaice and Flounder (Pleuronectes) — Soles (Solea) — Blind Soles (Soleotalpa) — The Tube-Bladdered Fishes (Suborder Physostomi) — Eel Tribe (MurcenicUe) — Muraenas (Mxircena) — True Eels (Anguilla) — Congers (Conger) — Serpent-Eels (Ophichthys) — Deep-Sea Eels (Synaphobranchus) — Single-Slit Eels (Sym- branchida?) — Electric Eel (Gymnotidce) — Cat-Fishes (Siluridce) — Eel-Like Cat-Fish (Clarias)— Wels (Silurus)— Yarrell's Cat-Fish (Bagarius) — Electric Cat-Fishes (Mala- pterurus) — Mailed Cat-Fishes (Callichthys, etc.) — Carp Tribe (Cyprinidce) — True Carp (Gyprinus) — Crucian and Golden Carp (Carassius) — Barbels (Barbus) — Gudgeon (Gobio) — White-Fish (Leuciscus) — Tench (Tinea) — Beaked Carp (Chondrostoma) — Bitterling (Rhodeus) — Bream (Abramis) — Rapfen (Aspius) — Bleak (Alburnus) — Sichel (Pelecus) Loaches (Gobitis, etc.) — African Loaches (Kneriida) — Characinoid Fishes (Enjthrinido?) Cyprinodonts (Gyprinodontidoz) — Double-Eyes (Anableps) — Blind-Fish (Amblyopsidm) Umbres (Umbridce) — Pike (Esocidai) — African Beaked-Fish (Mormyridw) — Feather- Backs (Notopteridw) — Southern Pikelets (Galaxiida>) — Arapaimas (Osteoglossidcc) — Arapaima (Arapaima) — Barbelled Arapaima (Osteoglossum) — Small-Mouthed Arapaima (Heterotis) — Moon-Eye (Hyodontidai) — Chisel-Jaw (Pantodontida?) — Beaked Salmon (Gonorhynchidoj) — The Scopeloids (Scopelidce) — Phosphorescent Scopeloids (Stemopty- chido3 and Stomateidce) — Silvery Light-Fish (Photichthys) — Hedgehog-Mouths (Echio- stoma) — The Dorab (Chirocentridai) — Long-Finned Herring (Bathythrissidai) — The Extinct Saurodonts (Enchodontidw, Saurocephalidce, etc.) — The Herring Tribe (Clupeidce) — Typical Group (Glupea) — Fresh- Water Herrings (Diplomystus) — Anchovies (Engraulis) — Elops — Slender-Scales (Leptolepis) — The Smooth-Heads (Alepocephalidce) — Southern Salmon (Haplochitonidai) — Salmon Tribe (Salmonidce) — Typical Group (Salmo) — Salmon — Trout — Charr — Many-Rayed Salmon (Onchorhynchus) — Smelts (Osmerus) — Coregonoids (Goregonus) — Grayling (Thymallus) — Percopsidce — Bony Pike and its Kindred (Suborder JEfheospondyli) — Existing Types (Lepidosteidce) — Spear-Beaks (Aspidorhynchida}) — The Bow-Fin and its Allies (Suborder Protospondyli) — Existing Family (Amiidce) — Extinct Families (Pachycormidce, etc.) — The Sturgeon Tribe (Sub- order Chondrostei) — Toothed Sturgeons (Polyodontidcs) — Toothless Sturgeons — (Acipen- seridm) — True Sturgeons (Acipenser) — Shovel-Beaked Sturgeons (Scaphirhynchus) — Allied Extinct Families (Chondrosteidaz, etc.) — Fringe-Finned Ganoids (Order Cros- sopterygii) — Existing Species (Polypteridm) — Extinct Families, .... 333- CHAPTER IV. — Sharks and Rats, — Subclass Elasmobranchii. Distinctive Features— The Blue Shark and its Allies (Carcharnda;)— Typical Genus (Car- charias) — Tope (Galeus) — Hammerheads (Sphyrna) — Hounds (Mustelus) — Porbeagle Group (Lamnidai) —Porbeagles (Lamna) — Rondeleti's Shark (Carcharodon)— Fox-Shark (Alopecias) — Basking-Shark (Cetorhinus)— Indo-Pacific Basking-Shark (Rhinodontidai) — Dog-Fishes and Their Allies (Scylliidm)— True Dog-Fishes (Scyllium) — Other Genera— Pavement-Toothed Sharks (Cestraciontid(c) — Comb-Toothed Sharks (Noti- danidce)— Typical Genus (Notidanus) — Frill-Gilled Shark (Chlamydoselache) — The Spiny Dog-Fishes and their Allies (Spinacidce)— The Extinct Petalodonts (Petalodon- tidai)—The Angel-Fish (Squatinidai)— The Saw-Fishes (Pristiophoridm and Pristidoz)— CONTENTS Side-Gilled Saw-Fishes (Pristiophorus) — True Saw-Fishes (Pristis)— Beaked Rays (Rhinobatidce) — Typical Genus (Rhinobatis) — Bhynchobatis — The True Rays, or Skates (Raiidce) — Electric Rays (Torpedinidai) — The Eagle-Rays (Myliobatidw) — Typical Genus (Myliobatis) — Other Genera (Aetobatis, etc.)— Sting-Rays (Trygonidce) — Lobe-Finned Sharks (Ichthyotomi) — Fold - Finned Sharks (Cladodontia) — Spine - Finned Sharks (Acanthodii), . . . ... 520 THE LOWEST VERTEBRATES AND THEIR ALLIES CHAPTER I. — The Lamprey Group, — Class Cyclostomatb. Characters of Chordates and Non-Chordates — Lampreys and Hag-Fishes (Subclass Marsipobranchii) — True Lampreys (Petromyzum) — Southern Lampreys (Mordacia, etc.) — Hag-Fishes (Myxinidce) — Primeval Lampreys (Palceospondylus), . . . 549 CHAPTER II. — The Armoubed Primeval Vertebrates, — Subclass Ostracophori. Pteraspis — Cephalaspis — Pterichthys, ........ 555 CHAPTER III. — The Lancelets, — Subkingdom Protochordata — Class Leptocardii. Common Lancelets (Branchiostoma), ........ 558 CHAPTER IV. —The Sea-Squirts or Ascidians, — Class Tunicata. Structure of Ascidians — Development — Typical Ascidians — Non-Luminous Pelagic Ascidians — Tailed Ascidians, . ...... 561 CHAPTER V. — Worm-Like Protochordates, — Class Enteropneusta. Balanoglossus — Other Forms — Ancestry of Chordates, ...... 573 Index ............ 577 LIST OF ILLUSTRATIONS COLOURED PLATES Rat-Snake and Cobras, Soft River-Tortoises, . The Black Iguana, Water-Monitors Robbing a Nest, Wall Lizards, Chameleons, Chimera, .... Gurnards, Globe-Fish and Coffer-Fish, . Flat-Fish, A Salmon Leap, . Blue Shark, Frontispiece Facing page 99 128 152 163 „ 172 332 383 428 „ 441 496 522 PAGE PLATES Black Caimans at Home, Giant Tortoises of the Galapagos Islands, Rough-Tailed Agama Basking, A Family of Vipers, Group of Scaly-Finned Fishes, Giant and Common Sturgeons, ascidians, Page Facing 11 54 105 231 342 511 549 TEXT ENGRAVINGS REPTILES Mississippi Alligator, Skull of Crocodile, Pelvis of Dinosaur, Skeleton of Ichthyosaur, . Skeleton of Armoured Dinosaur, Tooth of Plesiosaur, Skull of Cyamodus, Skull of Flying Dragon, . Vertebra of Dinosaur, Vertebra of Fish-Lizard, . PAOE 1 2 3 4 4 Vertebra of Snake, Skeleton of Crocodile, Skull of Extinct Crocodile Spectacled Caiman, Mississippi Alligator, Stumpy Crocodile, Estuarine Crocodile, Nile Crocodile, Sharp- Nosed Crocodile, Long-Nosed Crocodile, 6 10 13 16 19 21 23 24 26 28 xu LIST OF ILL USTRA TIONS Gangetic Garial, 30 Restoration of the Iguanodon, 33 Vertebra of Dinosaur, 34 Tooth of Hoplosaur, 34 Tooth of Pelorosaur, 35 Hind-Foot of Dinosaur, 35 Huckle-Bone and Tibia of Megalo saur, . 36 Skeleton of Claosaur, 36 Tooth of Iguanodon, 37 Teeth of Trachodon, 37 Toe-Bone of Armoured Dinosaur, 37 Skull of Horned Dinosaur, 38 Restored Skeleton of Horned Dint )saur, . 39 Skeleton of Pterodactyle, . 40 Restoration of Long- Tailed Pterod actyle, . 41 Shells of Chaibassa Terrapin, 42 Skull of Gangetic Soft- Tortoise, 43 Skeleton of Tortoise, 44 Diagram of Plates on Shell of a T< irtoise, . 45 Plastron of Chaibassa Terrapin, 47 Skull of Tortoise, . 47 Brazilian Tortoise, . 49 Shell of Burmese Brown Tortoise, 51 Elegant Tortoise, . 52 Elephant-Tortoise, . 56 Grecian Tortoise, . 60 Areolated Tortoise, 62 Dentated Hinged Tortoise, 63 Bell's Hinged Tortoise, 64 Chaibassa Terrapin, 66 Carolina Box-Tortoise, 67 European Pond-Tortoise, . 69 Sculptured Terrapin, 71 Carapace of Hamilton's Terrapin, 72 Painted Terrapin, . 73 Carapace of Smith's Batagur, 74 Skull of Big- Headed Tortoise, 75 Big-Headed Tortoise, 76 Pennsylvanian Mud-Terrapin, 77 Alligator- Terrapin, 79 Green Turtle, 82 Hawksbill Turtles Swimming, 83 Young Loggerhead Turtle, 84 Leathery Turtle, . 87 Humerus of Extinct Leathery Tu rtle, . 88 Skull and Jaw of Greaved Tortois e, . 89 Front of Plastron of Side-Neck ed Tor- toise, . 89 Carapace of Black Sternothere, 90 Matamata Tortoise, 91 Snake- Necked Tortoise, 92 American Side-Necked Tortoise, 93 Giant Amazonian Tortoise, 94 Skull of Horned Tortoise, . 97 Carapace of Wide-Shielded Wealden Tor toise, . Cantor's Soft-Tortoise, Skeleton of Plesiosaur, Skull of Simosaur, Vertebra of a Plesiosaur ian, Skeleton of Lariosaur, Vertebra of a Snake, Skeleton of Lizard, Lobe-Footed Gecko, Turkish Gecko, Fringed Gecko, Wall-Geckos, Common Scale-Footed Lizard, Armed Agama, Sail-Tailed Lizard, Arabian Thorny-Tailed Lizard, Moloch Lizard, Red-Throated Anolis, Helmeted Basilisk, Stilted Lizard, Galapagos Sea-Lizard, Galajiagos Land-Lizard, Ring- Tailed Iguana, Horned Lizard, Cape Girdle-Tailed Lizard, Common Scheltopusik, The Blind-Worm, . Arizona Poisonous Lizard, Cape Monitor, TheTeju, . Surinam Ameiva, . Handed Amphisbsena, Spotted Aniphisbsena, Green Lizards, Viviparous Lizard, Algerian Keeled Lizards, . Common Fringe-Toed Lizards, Stump-Tailed Lizards, European Snake-Eyed Lizard, Common Skink, Three-Toed Bronze Lizard, Head of Snake, Skeleton of Snake, Indian Python crushing its Prey, African Python swallowing a Bird Australian Diamond-Snake, Streaked Tree-Boa, Dog-Headed Tree-Boa, The Home of the Anaconda, Common Boa, Egyptian Sand-Snake, Coral Cylinder-Snake, A Shield -Tailed Snake, LIST OF ILLUSTRATIONS Xlll Javan Wart-Snake, Ringed Snake seizing its Prey, Viperine and Tesselated Snakes, . Keel-Tailed Snake, Javan Pigmy Snake, The Dark Green Snake, Black- Marked and Horseshoe -Snakes, iEsculapian Snake, Leopard-Snake, The Four- Rayed Snake, . Sipo, or Brazilian Wood-Snake, . Crowned Moon-Snake, Cat-Snake, .... Coral-Snake, Long-Glanded Snake and Masked Adder, Banded Adder, or Raj -Samp, Young Giant Cobra, or Hamadryad, Short Death - Adder and Spine - Tailed Death- Adder, . Banded Sea-Snake, Black-Banded Sea-Snake, . Long-Nosed, or Sand- Viper, . PAGE 199 201 202 203 204 206 208 210 211 212 213 215 216 219 220 221 223 225 227 228 233 Russell's Viper, The Puff- Adder, . Horned Vipers in the Sand, The Eja, or Desert Saw-Viper, Common Rattle-Snake, Diamond and South American Rattle Snakes, The Bushmaster, . Siberian Halys Viper, Copper-Head, or Moccasin-Snake, Climbing Pit- Viper, Rat-Tailed Pit- Viper, Skeleton of Fish - Lizard containing Young, Paddle of Fish-Lizard, New Zealand Tuatera, Skull of Hyperodapedon, . Pelvis and Shoulder-Girdle of an Anomo dont, .... Skull of Pavement-Toothed Anomodont, Skull of Wall-Toothed Anomodont, Skull and Teeth of Galesaur, AMPHIBIANS Fire-Bellied Frogs, Bull-Frogs Disporting, Skeleton of Salamander, Skeleton of Frog, . Development of the Frog, Moor-Frogs, Agile Frogs, Javan Flying Frog, Variable Tree-Frogs, East African Short-Headed Frogs, Solomon Island Sharp-Nosed Frog, Argentine Horned Frogs, or Escuerzos, Mexican Sharp-Nosed Toad, Grasshopper-Frogs, European Tree-Frogs, Male Midwife Frog, with Chains of Eggs, Smooth Spur-Toed Frog and its Tadpole Female Surinam Water-Toad, PAGE 257 259 260 261 262 264 267 269 270 272 274 275 278 279 281 285 287 288 Alpine Newts, Spotted Salamander, Alpine Salamander, Male and Female of Marbled Newt, Male and Female of Common Newt, . Spectacled Salamander, Larval Stage of Mexican Axolotl, . Adult of Mexican Axolotl, Giant Salamander, Hell-Bender, or Mississippi Salamander, Three-Toed, or Eel-Like Salamander, The Olm, .... Siren Salamander, . A Worm- Like Amphibian, Skeletons of Primeval Salamanders, Skull of Mastodonsaur, Vertebrae of Primeval Salamander Skull of Metoposaur, PAGE 234 235 236 237 239 241 242 244 245 246 247 251 251 253 254 255 256 256 256 PAGE 289 292 293 295 297 299 300 301 303 305 306 307 309 310 311 312 312 313 FISHES Flying Fish, . . . . Skeleton of Perch, . . . . Skeleton of Extinct Fringe-Finned Shark, Skeleton of Sturgeon, Skeleton of Fin of Fringe-Finned Shark, Skull of Australian Lung-Fish, . Palatal Teeth of Extinct Lung-Fish, Australian Lung- Fish, PAGE 314 316 317 318 319 325 326 327 PAGE South- American Mud-Fish, . . 328 African Mud-Fish, . . .329 Restoration of Berry-Bone Fish, . . 331 Pike-Perch and Common Perch, . . 334 Danubian Perches and Ruffe, . . 337 Common Bass, Sea-Perch, and Stone-Bass, 339 Striped Red Mullet, . . .345 Sargo and Gilt-Head, . . . 347 XIV LIST OF ILLUSTRATIONS Australian Knife-Jawed Fish, Spotted Firm-Fin, . Australian Long-Fin, Bleeker's Plesiops, . Schomburgk's Many- Spine, Group of Spine-Finned Fishes, New Zealand Trachichthys, Common Meagre, . Spotted Indian Sword-Fish, Scabbard-Fish, Common Mackerel and Horse-Mackerel, Pilot-Fish, . Coryphsena, New Zealand Gastrochisma Sucking-Fishes, Star-Gazer and Weaver, . Tile-Fish, . Hoedt's Soft-Spine, Barracuda and Angler-Fish, Common Bull- Heads, Sapphirine Gurnards, Armed Bull-Head, Beaked Gurnard, . Australian Dragon-Fish, . Lump-Sucker and Viviparous Blenny, Fresh-Water Goby, Mud-Skippers Disporting, New Zealand Thorny-Nose, Japanese Chirus, . Oblique-Spined Blenny, . Indian Spiny Eel and Oil-Fish, Sand-Smelt and Square-Tail, Common Grey Mullet, Gar- Pike, . Group of Sticklebacks, Two-Spotted Sucker-Fish, Striated Serpent- Head, Climbing- Perch on Land, Paradise-Fish and Telescope-Fish, The Gurami, Pike-Head, Unicorn-Fish, Banks's Ribbon-Fish, Bisso's Thornback, . Silver-Dotted Pomacentrus, Striped Wrasse, Silvery Viviparous Wrasse, Tristram's Chromid, Blue-Finned Tube-Mouth, Pipe-Fish and Sea- Horse, Fucus-Like Sea- Horse, Eel-Like Lycodes, . Haddock, Whiting, and Cod, Burbot and Wels, . PAGE 348 349 350 352 353 354 355 357 359 361 364 365 368 370 372 374 376 377 379 381 383 384 385 386 387 388 390 392 393 395 396 398 399 401 404 407 409 410 412 413 414 415 416 417 418 420 421 422 424 425 426 431 432 436 PAGE Parasitic Fish in Pearl-Shell, . . 438 Lesser Sand-Eel, .... 439 Mediterranean Muraena, . . . 446 Eels in the Mud, . . . .447 Bengal Short-Tailed Eel, . . . 450 Electric Eel, .... 451 Group of Carp, .... 457 Group of White-Fisb, . . . 460 Tench, . . . 461 Bitterling, Bleak, and Gudgeon, . . 462 Group of Bream, .... 464 Sichel, Rapfen, and Beaked Carp, . 465 Group of Loaches, .... 467 Angola Loach, .... 468 The Piraya, . . . .469 Head of Cyprinodont, . . . 470 Female and Male Double-Eye, . .471 Kentucky Blind- Fish, . . .472 Common Pike, .... 473 Beaked Fish and Slender Pikelet, . 475 Bornean Feather- Back, . . . 476 Brazilian Arapaima, . . . 477 Cliisel-Jaw and Moon- Eye, . . 479 Beaked Salmon, .... 480 Phosphorescent Sardine, . . . 482 Silvery Light-Fish and Hedgehog- Mouth, 483 The Dorab, . . . .484 Long- Finned Herring, . . . 485 Skeleton of a Saurodont, . . . 486 Shad, Sprats, and Herring, . . 488 Black Smooth-Head, . . .491 Zebra Salmon, .... 492 Salmon and Sea-Trout, . . .493 May-Trout and Hucho, . . .499 Grayling and Charr, . . . 501 Common Smelt, .... 503 Maranes, ..... 505 Bony-Pike,. . . . .507 The Bow-Fin, . . . .508 Skeleton of Extinct Amioid, . . 509 Jaw of Pycnodont, .... 509 Giant Scale-Tooth,. . . .510 Spoon-Beaked Sturgeon, . . .513 Sterlet, 515 Extinct Acipenseroid Fish, . . 516 The Bichir, . . . .517 Skeleton of Hollow-Spined Ganoid, . 518 Hammer-Headed Shark, . . .521 Spiny Dog-Fish and Smooth-Hound, . 525 Indo-Pacific Basking- Shark, . . 528 Lesser Spotted Dog-Fish and its Eggs, . 529 Port Jackson Shark, . . .531 Lower Jaw of Port Jackson Shark, . 531 Teeth of Comb-Toothed Sharks, . . 532 LIST OF ILLUSTRATIONS xv PAGE Frill-Gilled Shark, . 533 Angel-Fish, . 536 Japanese Saw-Fish, . 537 Halavi Ray, . 539 Thornback Skates, . 540 Jaws of Thornback, Common Skate and Marbled Electric Ray, Teeth of Lobe-Finned Shark, Restoration of Fold- Finned Shark, Restoration of Spine-Finned Shark, PAGE 541 542 546 547 547 THE LOWEST VERTEBRATES AND THEIR ALLIES A Cartilaginous Sea-Squirt (Phallusia), Pear-Shaped Ascidian (Hijpobythius), A Creeping Ascidian (Clavelina), . An Incrusting Ascidian (Botrylloides), A Compound Ascidian (Amarucium), An Individual of a Chain-Salpa, . Botryllus, .... Young Balanoglossus, A Pyrosoma Colony, Group of Lampreys, PAGE 551 Hag-Fish, .... 553 Skeleton of Primeval Lamprey, . 554 Restoration of Pteraspis, . 555 Restoration of Cephalaspis, 556 Restoration of Pterichthys, . 556 Lancelet, .... 558 A Leathery Sea-Squirt (Microcosmus), 561 Section of Sea-Squirt, 562 PAGE 565 566 567 568 568 570' 572 573 576 ERRATA PAGE 47. Line 18 from top, after "yet" add "except in the leathery turtle." 77. Line 4 from top, for " rib-process " read " rib-like process." 79. Lines 2 and 3 from top, for " the majority of the vertebrae of the tail have the articular cup behind and the ball in front " read " the nuchal bones give off rib-like processes underlying the marginals." 169. Line 6 from bottom, for " Z\ " read " 8£." 178. Line 10 from bottom, for "African" read "Oriental." 180. Lines 21 and 22 from bottom, transpose "upper" and "lower." 186. Line 12 from bottom, for " New' Island " read " New Ireland." 245. Line 7 from top,/o7' "heavy" read "horny." 266. Line 4 from top, for "Australia" read "Papua." 273. Line 12 from bottom, after "and" add "almost." 274. Line 8 from top, for " vertical " read "horizontal." 302. Line 4 from top, for " Hypnobius " read " Hynobius " ; line 22, omit " only." 333. In table, delete " (6) Suborder Isospoxdyli — Leptolepis " ; and on p. 334, line 7 from top, for " eight " read " seven." 362, 397. The species of Thyrsites and Sphyraim are both termed "barracudas" ; the latter may be distinguished as " barracuda-pikes." The account of the fishing of the latter refers to the former. 527. Line 29 from top, for " Iceland " read " Ireland." 532. Line 25 from bottom, instead of " four . . . five or six " read " five ... six or seven." •534. Line 2 from top, for " developed " read " depressed." THE ROYAL NATURAL HISTORY. ■&AMBIER :BOLT:ON./TZ.S. REPTILES. CHAPTER I. General Characteristics, — Class Reptilia. In ordinary language the term Reptile is applied indifferently to such creatures as crocodiles, tortoises, lizards, snakes, frogs, and salamanders, but by the naturalist it is used in a more restricted sense, and includes only the first four of these, together with a host of extinct types; while the frogs and salamanders, with certain other forms, both living and extinct, on account of important structural differences, constitute a class by themselves, known as the Amphibians, and bearing the same rank as the class of Reptiles. To an ordinary observer there would seem but little in common between a scaled lizard or snake, a cuirassed crocodile, and a carapaced tortoise, on the one hand, and a feathered bird on the other. Nevertheless, as we have had occasion to mention at the close of the preceding volume, the connection between Reptiles and Birds is exceedingly intimate, — so close, indeed, that Professor Huxley has termed the latter greatly vol. v. — I REPTILES. modified Reptiles. At the present day the two groups are, indeed, somewhat widely sundered; and it is only by the study of forms long since extinct that we are enabled to grasp the intimate relationship that exists between them. That Birds are the descendants of Reptiles may accordingly be taken for granted, although we are still unacquainted with the immediate links connecting the two classes. In another direction Reptiles are, however, connected through other extinct forms with the Amphibians ; while from these intermediate, half - Reptile, half- Amphibian creatures, it is probable, as elsewhere mentioned, that Mammals have originated. As we shall point out later on, Amphibians are also intimately con- nected with the class of Fishes, and we thus see how closely allied are all the classes of the Vertebrates, and how difficult is the task of the naturalist to dis- tinguish them satisfactorily one from another when the whole of the extinct forms are taken into consideration. It is, indeed, solely from the still imperfect condition of our knowledge of the past that we are enabled to formulate any definitions at all, for had we the whole chain of organised nature before us, it will be obvious that no breaks would exist, but that every group would pass by imperceptible degrees into the earlier one from which it originated. Proceeding to the consideration of what constitutes a Reptile, as distinct from any other animal, we may first point out some of the features in which Reptiles agree with Birds, and thereby differ from Mammals. In the first place, the skull articulates with the first A^ertebra by a single knob, or condyle (V of the figure) ; while each half of the lower jaw is composed of several distinct bones; and the whole lower jaw articulates with the skull by the intervention of a separate quadrate-bone.1 Then, again, both agree in that the appendages developed from the outer layer of the skin never take the form of hairs, while the young are not nourished by means of milk secreted by special glands on the body of the female parent, neither are gills developed at any period of life, throughout which respiration is effected by means of lungs. A further resemblance is shown in the position of the ankle-joint between the upper and lower rows of small bones entering into the composition of that part of the skeleton. In producing their young from eggs (sometimes retained within the body of the parent until hatched), Reptiles resemble not only Birds, but likewise the lowest Mammals ; with which they also agree in the nature of the investments surrounding the embryo. As regards the distinction between the two groups, Reptiles are broadly 1 In the figure the quadrate-hones are the prominences at the hinder external angles on either side of the letter N. LOWER AND UPPER SURFACES OF THE SKULL OF A CROCODILE. X, aperture of the internal or posterior nostrils ; 0, sockets of the eyes ; P, vacuities of the palate ; T, frontal vacuities, or fossae ; V, condyle of the occiput. GENERAL CHARACTERISTICS. separated from Birds by the absence of feathers; the appendages of the outer layer of the skin being in the form either of overlapping horny scales, or of large shields uniting by their opposed edges. Moreover, all known Reptiles differ from Birds in having more than three digits in the fore-limb ; while in no cases are the collar-hones fused into a furcula, as they are in all flying Birds. A further distinction is to be found in connection with the circulatory system, the blood of all existing Reptiles being cold, while the aorta, or great propelling blood-vessel of the heart is double, and crosses both branches (in- stead of only the left branch) of the windpipe. It will be obvious, however, that these two last characters cannot be verified in the case of extinct Reptiles, among which it is quite probable that there may have been some in which the blood was warm. A similar remark will apply to the absence among living Reptiles of those ramifica- tions of the bronchial tubes throughout the body, which form such a characteristic feature in the structure of Birds. As additional features in the skeleton, it may be noticed that Reptiles never have the terminal faces of the vertebrae saddle-shaped ; while in those forms in which the number of toes in the hind-limb is reduced to three, the metatarsal bones do not unite to form a cannon-bone in conjunction with the lower row of bones belonging to the ankle-joint. Then, again, with the exception of one remarkable extinct group, Reptiles, as a rule, are characterised by the three bones of the pelvis remaining distinct from one another through life ; whereas in all existing birds they are welded together. There are likewise differences in regard to the form and structure of the breast-bone and sacrum, into the consideration of which it will be unnecessary to enter in this work. Diversity of In marked contrast to the uniformity in appearance and structure Form and characterising Birds, the various groups of Reptiles differ widely from cture> one another, both as regards external form and internal structure. Externally, a lizard, a snake, and a tortoise present the most marked differences in general appearance among living members of the order ; while among extinct types there were some which walked on their hind-limbs alone, after the manner of Birds, and others having their fore-limbs modified into wings and the digits connected THE BONES OP THE LEFT SIDE OF THE PELVIS OF AN EXTINCT DINOSAURIAN REPTILE (^ Iiat. size). il, ilium : p, pubis ; is, ischium. — After Marsh. 4 REPTILES. by a leathery membrane like that of bats. In a typical Reptile, such as a lizard or crocodile, both pairs of limbs are well developed, and of approximately equal length ; but in the snakes all external traces of limbs have disappeared ; while in the extinct flying dragons, or Pterodactyles, the fore-limbs much exceed the hind ones in size, and in many of the so-called Dinosaurs, which are likewise extinct, the excess in size falls to the share of the hinder pair of limbs. In other cases, again, the limbs may be modified into paddles, adapted for progres- SKELETON OF FISH-LIZARD, OR ICHTHYOSAUR. sion in the water, as in the existing turtles, and the extinct fish -lizards or Ichthyosaurs ; the body in the latter assuming a somewhat fish-like form. In nearly all cases Reptiles have long and well-developed tails ; although in some of the flying dragons these be- come rudimentary. A large number of Rep- tiles are characterised by the development of bony plates within the deep layer of the skin; such plates, which are well displayed in existing crocodiles, being overlain by horny shields, and thus corresponding in every re- spect with those forming the carapaces of the arm- adilloes among Mammals. sc, shoulder-blade, or scapula; co, coracoid ; h, upper arm-bone, or Among certain extinct humerus ; r, u, bones of fore-arm, or radius and ulna ; c, wrist or carpus ; Dinosaurs these bony plates mc, metacarpus ; il, haunch-bone, or ilium ; p, pubis ; is, ischium ; f, thigh-bone, or femur ; ti, fi, bones of lower leg, or tibia and fibula ; ta, ankle, or tarsus ; mt, metatarsus. — After Marsh. RESTORED SKELETON OF ARMOURED DINOSAUR (about -fa nat. size). attain a development un- paralleled at the present day ; and in some they are believed to have occupied the extraordinary position shown in the accompanying figure. Still more remarkable differences exist with regard to the form and structure of the teeth; which, instead of being, as in the two preceding classes, strictly confined to the borders of the jaws, may be spread' over the entire palate. In spite, however, of this diversity of form, the teeth of Reptiles differ from many of those of the majority of Mammals in that they are never implanted in the GENERAL CHARACTERISTICS. 5 jaws by two or more roots ; while in no cases are their crowns complicated by the presence of infoldings of enamel. The simplest type of reptilian tooth is in the form of a cone; such conical teeth being confined to the margins of the jaws, where, as among crocodiles, they may be implanted in distinct sockets, or, as in the extinct fish -lizards, in an open groove. In other cases, as among lizards, teeth of the same general type may be united by a bony deposit either to the summit or to one side of the margin of the jaw. In place of the one regular re- placement, characteris- ing the anterior teeth of the majority of Mam- mals, the teeth of most Reptiles are replaced irregularly and continu- ously throughout life ; the successional teeth growing up beneath the bases of those in use, and gradually causing an absorp- tion of their roots. When teeth are distributed over the whole or a greater portion of the palate, they generally assume a more or less flattened and bean- like shape, so as to form a kind of pavement in the mouth, as shown in the accompanying figure of the under surface of the skull of an extinct reptile. CONICAL TOOTH OP AN EXTINCT PLESIO- SAURIAN BEPTILE. UNDER SURFACE OP SKULL OP AN EXTINCT reptile {Cyamodus), with pavement - like TEETH ON THE PALATE. LEFT SIDE OF THE SKULL OF A BEAKED FLYING DRAGON (J nat. size). a, vacuity in front of the eye ; b, socket of the eye ; c, occipital spine ; d, angle of lower jaw ; e, extremity of upper, and e', of lower jaw ; q, articulation of the skull proper with the lower jaw ; s, point where the two branches of the lower jaw diverge. — After Marsh. Between conical and pavement - like teeth there are various intermediate grades, some of which will be referred to in the sequel. It is, however, by no means all members of the class that are provided with teeth ; the tortoises and turtles being living examples of the total loss of these organs, and the consequent conver- REPTILES. sion of the jaws into horn-clad beaks. Certain representatives of the extinct flying dragons were likewise devoid of teeth; and as in these forms the horn- covered jaws were long and narrow, the resemblance to the beak of a bird becomes most marked. It has already been stated that the vertebras of Reptiles never articulate by means of those saddle-shaped surfaces so characteristic of Birds. They present, however, great diversity of structure in this respect. In some cases, for instance, as in the fish-lizards, the bodies or central portions of the vertebras are very short from front to back, and have concave surfaces both in front and behind for mutual articula- tion. In marked contrast to this type is the LEFT-SIDE VIEW OF A NECK VERTEBRA. OF A DINOSAUR. b, anterior ball. — After Marsh. SIDE AND FRONT VIEWS OF THE BODY OF A FISH-LIZARD. )F A VERTEBRA a, b, attachment of ribs. neck vertebra of a Dinosaur, where the anterior end of the body of each vertebra forms a convex knob (b), received into a cup at the posterior end of the vertebra in advance.1 In other instances, as in the existing crocodiles and lizards, an arrangement pre- cisely the reverse of the last is pre- sent ; that is to say, the ball is at the hinder end, and the cup at the front of the body of the vertebra. In a few lizards and in all snakes the ver- tebras are further complicated by the development of additional articular facets, taking the form of wedge-like projections from one vertebra, which are received into cavern-like excavations in the adjacent one. 1 It should be mentioned that in this figure only the portion of which b is the extremity corresponds with the whole of the specimen represented in the other figure on the same line. FRONT AND BACK VIEWS OF A VERTEBRA OF A SNAKE. zi indicates the additional articular process, which is received into the cavity zi1. CLASSIFICATION. 7 Omitting mention of certain features connected with their osteology, it may- be observed that among those reptiles with four or five toes to each foot, while a few, such as certain tortoises, have the same number of joints in each toe as Mammals, — that is to say, two in the first toe, and three in each of the others, — in the greater majority there is a departure from this simple arrangement. In the lizards, for instance, the number of joints in the toes (reckoning from the first to the fifth digit) is 2, 3, 4, 5, 3 in the fore-limb, and 2, 3, 4, 5, 4 in the hind-limb ; while in crocodiles, where there are but four toes in the latter, the numbers are respectively 2, 3, 4, 4, 3, and 2, 3, 4, 4. In this increasing number of joints in the toes from the first to the fourth, such reptiles approximate to birds. As regards their soft internal parts, Reptiles are characterised by the low development of their brains ; which, in conjunction with their cold blood, accounts for the generally sluggish movements of their existing representatives. With the exception of the crocodiles, Reptiles differ from Birds in that the heart has only three, in place of four, complete chambers, thus causing the freshly oxygenated blood returning from the lungs to be mixed with the effete blood which has traversed the body. Even in crocodiles, where the heart has practically four chambers, the fresh and effete blood is partially mingled, owing to a communica- tion between the vessels just outside the heart. Like Birds, Reptiles never have a midriff' completely separating the cavity of the chest from that of the abdomen. Classification Reptiles having come into existence at an earlier period than and Distribution. either Mammals or Birds, and attaining an enormous development during epochs when both those groups were but feebly represented, it would be only natural to expect that they should have suffered to a much greater extent by the extinction of types with the lapse of time. As a matter of fact this is found to be the case ; the number of existing orders of Reptiles being now but four (of which one is represented by only one or two species), whereas, if we include the extinct types, at least nine orders may be recognised. These nine orders, of which the extinct ones are indicated by asterisks (*) may be named and arranged as follows, viz. : — 1. Crocodiles — Crocodilia. *2. Dinosaurs — Dinosauria. *3. Flying Dragons — Ornithosauria. 4. Tortoises and Turtles — Chelonia. *5. Plesiosaurians — Plesiosauria. 6. Lizards and Snakes — Squamata. *7. Fish-Lizards — Ichthyosauria. 8. Tuateras, or Beaked-Lizards — Rhynchocephalia. *9. Mammal-Like Reptiles — Anomodontia. Of these groups, by far the most numerously represented at the present day is the one containing the lizards and snakes, all of which are highly specialised forms, occupying a position in the class analogous to that held by the perching birds in the preceding class ; the majority being comparatively small or medium- sized forms. Next in point of numbers come the tortoises and turtles, all of which are protected by the presence of a bony carapace, and some of which attain very 8 REPTILES. large dimensions. The third numerical position in the fauna of the present day- is held by the crocodiles, of which there are some twenty-four species, all of relatively large size, and all more or less aquatic in their habits. The fourth existing order is now represented only by the lizard-like New Zealand tuateras, of which there is probably but a single species ; although in past times there were a host of allied forms. Of the five extinct orders the whole, or nearly the whole, of their representatives ceased to exist with the close of the Secondary period, that is to say, soon after the deposition of the chalk, and previous to that of the overlying London clay. During that long period, or " world of reptiles," the class attained a development which it never equalled before or since. The Dinosaurs, which were by far the largest of all land animals, then filled the place now occupied by Mammals ; the flying dragons played the rdle of the bats and birds of the present day ; while the marine Plesiosaurs and fish-lizards did duty for whales and porpoises. Of the mammal-like Reptiles, it will suffice to speak in the sequel. With regard to the past distribution of the four existing orders, it may be mentioned that the lizards and snakes, with the exception of two extinct suborders, are practically unknown before the commencement of the Tertiary period — that is to say, until after the deposition of the Chalk ; hence they may be regarded as essentially the Reptiles of the present day, when they attain their maximum development. The tortoises and turtles, although a much more ancient group, having existed throughout the Secondary period, are, however, still at or about their zenith. The case is, however, very different with the crocodiles, which were represented during the Secondary period by a host of forms quite unlike those of the present day, and probably more numerous' in species than their existing representatives. Many of the extinct crocodiles also exceeded any of the living forms in point of size. Still more markedly is this diminution noticeable in the case of the tuateras, in which a solitary survivor represents a once abundant group. Owing to the exigencies of space, our remarks on the present distribution of the class must necessarily be brief. In the first place, it may be observed that while no existing Reptiles are denizens of the air, only the turtles and sea-snakes are habitual inhabitants of the ocean. Of the terrestrial and fresh- water forms, it has been found that the distribution does not coincide very closely with that of Mammals and Birds, so that the zoological regions into which the globe has been mapped out from the geographical distribution of the latter scarcely hold good for Reptiles. This discrepancy may, no doubt, be partly explained by the very early period at which certain groups of the class, such as crocodiles and tortoises, spread themselves over the surface of the globe. As regards the dispersive powers of Reptiles in general, these, according to Dr. Gunther, are but limited. All these creatures, he writes, " are much specialised in their mode of life and propagation, and ill-adapted to accommodate themselves to a change of external conditions. As air-breathing, cold-blooded animals they are unable to withstand prolonged cold ; they are therefore entirely absent in the Arctic and Antarctic zones ; and such as escape the effects of the winter months in temperate zones by passing them in a torpid condition in well-sheltered places are not peculiarly organised forms, but offshoots from those inhabiting warmer climes. The tropical DISTRIBUTION. 9 and subtropical zones are the real home of the reptilian type, which there has reached its greatest development as regards size and variety of forms. In the north, Chelonians advance only to 50° latitude in the Western and to 56° in the Eastern Hemisphere ; lizards to about 56° in British Columbia, and close to the Arctic Circle in Europe ; while snakes disappear some degrees before the lizards. Also in the south, lizards extend into higher latitudes than snakes, namely, to the Straits of Magellan, whilst the latter do not seem to have advanced beyond 40° south latitude, and Chelonians to 36°." Of the various zoological regions into which the globe has been divided, the Oriental or Indian region, according to the same observer, is characterised by the number of fresh- water soft-tortoises l and S-necked tortoises,1 land-tortoises being scarce. Crocodiles, inclusive of the characteristic long-necked garials, are numerous, as are lizards and snakes — especially pythons. Africa is comparatively poorly off* for Reptiles, although characterised by its numerous land-tortoises, soft-tortoises, and side-necked tortoises ; x the crocodiles being represented only by members of the typical genus ; while lizards and snakes are comparatively numerous. Among the lizards, monitors, and among the snakes, pythons, are common to the Oriental and African regions ; while half of the exclusively Old World group of chamseleons are African. Madagascar is even more remarkable for the number of its chamseleons; its land and side-necked tortoises are numerous, although soft- tortoises, as in South America, are absent ; there is one crocodile ; and among the lizards the South American group of iguanas is abundant; while the snakes, among which none is poisonous, are also of a South American type. In the warmer parts of the Euro-Asiatic region (exclusive of India, etc.) the reptile fauna is mainly a mixture of Oriental and African types, although there are some peculiar forms. The only non-American alligator inhabits Central China. In the Australian or tropical Pacific region, exclusive of New Zealand, we meet with one group of land-tortoises, side-necked tortoises, and a crocodile ; while amongst the lizards there are skinks, geckos, monitors, and the so-called agamoids; the latter occurring in all the regions above mentioned, except Madagascar. Venomous snakes here outnumber the harmless ones. The Tropical and South American region is characterised by the presence of land and side-necked tortoises, to the exclusion of soft-tortoises. Crocodiles and caimans are numerous (the latter being characteristic) ; while of the abundant lizards the majority are iguanas, the true lizards (Lacertidce) of the Old World being replaced by the teiias (Teiidce) ; snakes are also numerous, among them being rattle-snakes and boas. In the North American region there are no caimans, their place being taken by an alligator ; while fresh-water S-necked tortoises, as well as soft-tortoises, replace the side-necked tortoises of the southern half of the continent. The snapping tortoises (Chelydriclce) are also mainly characteristic of this region, although one genus ranges as far south as Ecuador. As regards its lizards and snakes, this region presents the same relation to the preceding as is held by Euro- Asia to the Oriental and African regions. Lastly, New Zealand stands apart from all other countries in possessing the remarkable tuatera, in addition to which its only reptiles are skinks and geckos. 1 For the explanation of these and other names, the reader must refer to later chapters. CHAPTER II. Crocodiles, Dinosaurs, and Flying Dragons, — Orders Crocodilia. Dinosauria, and Ornithosauria. The living crocodiles, among which may be included in a general sense not only the reptiles to which that name more properly belongs, but likewise those commonly designated alligators, caimans, and garials, are the only existing representatives of three orders, which comprise among their members not only the most highly organised of all Reptiles, and those which approach nearest in their organisation to Birds, but likewise the largest of all terrestrial Reptiles, as, indeed, of any land animals. Although these three orders possess many character- istics in common, it will be more convenient to describe the leading features of each separately, in the course of which their common attributes will be pointed out. SKELETON AND ABDOMINAL RIBS OP CROCODILE. Characteristics Sluggish in disposition, hideous in form, and huge in size, of crocodiles, crocodiles alone among existing Reptiles serve in some measure to recall the giant Saurians with which the earth was peopled during earlier periods of its existence. In addition to their large bodily size, crocodiles are characterised by the lizard-like form of their bodies, which are supported on short limbs, and carried close to the ground. The long and powerful tail is much compressed from side to side, so as to be an efficient propeller in swimming ; its superficial extent being increased by a vertical longitudinal crest • on its upper surface, this crest GENERAL CHARACTERISTICS. 13 being formed of a double series of horny lobes in the basal half of the tail, beyond which it is single. The head terminates in a flattened snout of variable length, and is attached to the body by a short, although muscular neck ; while the bulky body is much depressed. The toes are more or less webbed. Externally, the back, tail, and under-parts of these animals are protected by an armour of quadrangular horny shields of varying size, which are arranged in regular longitudinal and transverse rows, and are in contact with one another by their edges. In the region of the back, and sometimes also on the under surface of the body, these horny shields are underlain by a corresponding series of pitted bony plates. In the region of the neck, among existing members of the order, these bony plates are often irregular in form, and vary in number, but on the back they are always quadrangular and broader than long, with a well-marked longitudinal ridge down the middle. Such plates form a considerable number of longitudinal rows ; each plate articulating by its edges with those on either side, while those of each transverse row overlap those immediately behind them. When a bony shield is developed on the under surface of the body, the number of longitudinal rows of plates in existing forms is always more than eight ; the transverse rows of plates overlapping and each plate being composed of two distinct pieces united together by suture. The limbs are provided with five toes in front and four behind ; the three innermost digits in each foot being furnished with claws. In all crocodiles, whether living or extinct, the conical teeth, which may be of very large size, are confined to the margins of the jaws, where they are implanted in distinct sockets ; while those in use are continually being replaced by fresh ones growing from beneath. These animals are further characterised by their nostrils opening at the extremity of the snout — which may be either short or long — and by their ears being covered with movable lids. Such are some of the leading external features of these reptiles, and although they would suffice to distinguish them from the living members of the order, they are insufficient to determine their true affinities. Laying stress upon the above-mentioned characters of their teeth, the naturalist is accordingly compelled to resort to the skeleton and soft internal parts for more distinctive characters. In the skull all crocodiles are characterised by the quadrate-bone (of which the position is indicated in the figure on p. 2) being firmly united with the adjoining bones ; while a further distinctive feature is to be found in the presence of two bony bars on the sides of the skull behind the socket for the eye, the uppermost of these arches being shown immediately below the ^^v^^— --£r^±faM^^^ letter T in the accompany- sn)E VIEW 0F gK.ULL 0P EXTINCT CROCodile (Peiagosaurus). ing figure, while the lower 0> socket for the eye ; T, temporal pit or fossa. and more slender one forms the backward continuation of the inferior margin of the eye-socket. The more anterior ribs (which, as in other Reptiles, are present in the neck as well as in the chest) generally articulate with the backbone by means of two distinct heads; and, while collar-bones are wanting, there is a breast-bone and likewise an inter- i4 CROCODILES. clavicle ; the latter being the median bar seen in the lower figure of the illustration on p. 10. A further peculiarity is the presence of seven or eight pairs of abdominal ribs in the wall of the abdomen, which have no connection with the proper ribs, and have their angle of union directed forwards.1 As regards the soft parts, the heart differs from that of all other living Reptiles in having four complete chambers, so that the fresh and impure blood can only mingle by means of a communication between the great vessels externally to the heart ; while there is also an incomplete midriff dividing the chest from the abdomen. In addition to the preceding characters, which are common to all members of the order, there are certain others found only in the existing forms and some of their nearest extinct allies. One of the most remarkable of these peculiarities is the extremely backward position of the aperture of the internal nostrils, which in the dried skull, as shown on p. 2, is situated close up to the occiput, this being due to the development of special plates by the bones of the palate, which grow beneath the nasal passage, so as to form a floor to it, and thus completely cut it off from the cavity of the mouth. As the summit of the windpipe is continued upwards into this posterior aperture of the nostrils, crocodiles are enabled to breathe while their mouths are wide open and filled with water. Another dis- tinctive feature of the group, also shown in the figure just referred to, is that the socket for the eye communicates freely behind with the lower temporal fossa. Then, again, all existing members of the order are characterised by the bodies of the vertebrae having the ball behind and the cup in front ; while the ribs of the chest are provided with hook-like or uncinate processes resembling those of birds. In the region of the neck the ribs present the peculiarity of having backwardly projecting and overlapping processes, which effectually prevent these animals from turning their heads to one side. Crocodiles are denizens of the tropical and subtropical regions of the globe, and are found in such latitudes wherever there are rivers or fresh- water lakes of sufficient size for their mode of life; while one of the Indian species habitually resorts to the sea-coast, where it has been seen floating at a considerable distance from the land. All of them are excellent swimmers, and are mainly propelled when in the water by the aid of their powerful tails ; the limbs being chiefly used when walking at the bottom of the water, or on the shore. When in repose, crocodiles lie like logs either in the water or on the banks of the lakes or rivers they inhabit ; but when in pursuit of their prey in the water they move with great speed, while they are also active on land. The young are, however, decidedly nimbler in their movements than are the adults. Exclusively carnivorous in the diet, some members of the order feed solely upon fish ; while others, in addition to fish, prey upon the flesh of all animals that come in their way. Adult crocodiles, writes Dr. Gunther, "attack every large animal which accidentally approaches them, and in overpowering it the whole of their powerful organisation is called into requisition. Seizing the victim between their capacious jaws, and fastening their long, pointed, conical teeth into its flesh, they draw it, in one moment, by their weight and with a stroke of the -tail, below the water and drown it. Their gullet is, however, much too narrow to allow of the passage of 1 These abdominal ribs, connected together by the ligament, are shown in the figure above referred to. EXISTING GROUP. 15 the entire body of the victim ; and their teeth being adapted for seizing and holding fast only, and not for biting, they are obliged to mangle the carcase, tearing off single pieces by sudden strong jerks." This rending process is mainly accomplished by lateral movements of the head and front portion of the body. Too often, human beings, who incautiously bathe in crocodile-haunted waters, fall victims to these bloodthirsty reptiles ; while there are instances of people being seized when merely stooping down to dip water from the river's marge. When seized, the only way for an unarmed man to escape is, it is said, to thrust his fingers into the creature's eyes and endeavour to gouge them out. To a consider- able extent crocodiles are nocturnal in their habits, and during protracted droughts many of them at least are accustomed to bury themselves in the mud, where they become torpid. As regards their reproduction, crocodiles lay from twenty to sixty eggs, of the approximate size of those of a goose, and invested with a hard, white shell. These are deposited in some hollow in the sand of the bank, where, after being covered to a greater or less depth, they are left to hatch. Whether the parent always assists in the incubation does not appear certain, although this has been proved to be the case in Madagascar by Dr. Voeltzkow. In that island the egg- laying season lasts from the end of August to the end of September; the usual number of eggs in a nest varying from twenty to thirty. The nest is excavated to a depth of about two feet in the dry white sand ; its lateral walls being under- mined so as to allow the eggs to roll into the cavities thus formed from the slightly elevated centre. Upon the summit of the completed nest, which is not noticeable externally, the parent sleeps ; and when the young crocodiles are ready for hatching they utter distinct notes, which are heard by the mother even through a layer of two feet of sand. Digging down to the eggs, the parent crocodile lays them open to the air, upon which the young reptiles make their way out by perforating the shell at one extremity by the aid of a tooth specially developed for this purpose, the whole process occupying as much as a couple of hours. When hatched, the young crocodiles are led to the water by their parent, whose attention they attract by uttering cries, which are, however, of a lower pitch than those emitted while still in the egg. Existing Crocodiles. Family Grocodilid^:. Caimans. The whole of the existing members of the order are included in a single family, which may be subdivided into half a dozen generic groups. Of these, in some respects the most specialised are the caimans and alligators, which, although closely allied, are now generally regarded as belonging to distinct genera. Both caimans and alligators are characterised by their rela- tively short and broad snouts, in which the edges of the jaws are festooned, and the nasal bones extend forwards to the aperture of the nostrils,1 while the two 1 This is shown in the figure on p. 2, where the nasals are the paired bones on the upper aspect of the skull, of which the narrow points just project into the cavity of the nostrils. i6 CROCODILES. halves of the lower jaw are united in front by a very short bony union. The stout teeth vary considerably in size in different parts of the jaws ; the third and ninth in the upper jaw, the fourth, and frequently also the first and eleventh, in the lower, being generally much larger than the others. In these features caimans and alligators resemble many of the true crocodiles ; from which they are distin- guished by the circumstance that, as a rule, both the first and the fourth tooth on each side of the lower jaw are received into pits in the upper jaw, so as to be invisible externally when the mouth is closed ; while the upper teeth bite on the outer side of the lower ones. Moreover, the number of teeth varies from seventeen SPECTACLED CAIMAN (fj nat. size). to twenty on each side of the upper jaw, and from seventeen to twenty-two in the lower jaw. Then, again, both these groups are characterised by the very small size of the upper temporal fossae on the top of the skull, or those marked T in the figure on p. 13 ; these fossae being in some cases completely obliterated. Caimans are specially distinguished by the aperture of the nostrils not being divided in two by the nasal bones, by the presence of a strongly developed bony armour on the inferior surface of the body, and by the bony plates on the upper surface being articulated together. Caimans, or jacares, as they are called by the natives of Brazil, are restricted to Central and South America, where they are represented by five species. Of these, the largest, and at the same time the best known, is the black or great CAIMANS. 17 caiman (Caiman niger), from the rivers of tropical South America eastwards of the Andes, which takes its name from the black of the upper surface of the body, the under-parts being yellow. This species, which generally attains a length of about 14 feet, is characterised by its partially bony and flat upper eyelid, by the presence of upper temporal fossae in the skull, by the number of teeth in each premaxillary or anterior upper jawbone being five, and the number of lower teeth being seventeen or eighteen. Nearly allied, although of much smaller size, are the broad-nosed caiman (C. latirostris), ranging from the Amazon to the Rio de la Plata, and the spectacled caiman (6^. sclerops), from Central and South America ; both of which have the upper eyelid rugose, with a small horn-like projection, while in the skull the socket of the eye does not extend so far forwards. Both are uniformly blackish when adult ; but in the former the skull is very wide, and the number of lower teeth from seventeen to eighteen, while in the latter the skull is narrower, and the lower teeth vary from eighteen to twenty. The two remaining species (C. trigonatus and C. palpebrosus) are still smaller, and characterised by the colour of the upper-parts being yellowish brown, spotted and barred with black ; while the upper eyelid is completely bony, the skull has no upper temporal fossa, there are but four teeth in each premaxillary bone, and the number of lower teeth is from twenty to twenty-two on each side. On the Amazon and Orinoco, as well as other South American rivers, caimans are to be met with in myriads, and appear to be very similar in their habits to the crocodiles of the Old World. Writing of the great caiman — jacare-uassu of the natives — Bates says that " it grows to a length of eighteen or twenty feet, and attains an enormous bulk. Like the turtles, the alligator [as he calls it] has its annual migrations, for it retreats to the interior pools and flooded forests in the dry season. During the months of high water, therefore, scarcely a single in- dividual is to be seen in the main river. In the middle part of the Lower Amazon, about Obydos and Villa Nova, where many of the lakes with their channels of communication with the trunk stream dry up in the fine months, the alligator buries itself in the mud and becomes dormant, sleeping till the rainy season returns. On the Upper Amazon, where the dry season is never excessive, it has not this habit. It is scarcely exaggerating to say that the waters of the Solimoens are as well stocked with large alligators as a ditch in England is in summer with tadpoles." By the natives of these regions the caiman is at once despised and feared ; the same traveller relating how on one occasion he saw a party boldly enter the water and pull to shore one of these large reptiles by its tail ; while at another time two medium-sized specimens that had been captured in a net were coolly returned to the water hard by where a couple of children were playing. Sometimes, however, they have to pay dearly for such temerity. The Indians of Guiana, according to Waterton, capture the caiman by means of a baited hook and line, the former being composed of several pieces of wood, which become fixed in the creature's jaws. Waterton's account of his ride on the back of a caiman thus caught is probably familiar to many of our readers ; and we have read of a similar feat being accomplished elsewhere. The eggs of the great caiman, which are about the size of those of a turkey, are said to be not unfrequently deposited in a heap of dry leaves, and are much sought after as food by the natives of Dutch Guiana. vol. v. — 2 18 CROCODILES. The early Spanish settlers of South America on meeting with a Alligators. ...... . gigantic lizard-like reptile naturally applied to it the name of una lagarta, which is the Spanish term for a lizard ; and this as naturally became in course of time corrupted into alligator. It would appear, indeed, that this name was first given to the caiman, to which in strict propriety it should therefore belong ; but now, by the common consent of naturalists, it is taken as the special designation of the members of the present genus. The alligators, as thus restricted, are represented by one species from North America, and by a second from the Yang-tse-Kiang in China; while there is also a third and imperfectly known species, of which the habitat is as yet undetermined. The alligators differ from the caimans merely by the forward prolongation of the nasal bones of the skull, so as to divide the aperture of the nostrils into two equal moieties, by the want of articulation between the bony plates of the back, and the absence or extreme thinness of those on the lower surface of the body. Curiously enough, the Chinese alligator (Alligator sinensis), which is a comparatively small species, is the one coming nearest in structure to the caimans ; this approximation being shown by the great development of bone in the upper eyelid, and the presence of thin bony plates on the lower surface of the body. The latter are, however, placed wide apart, without any mutual articulation or overlapping. In this species the front toes are free, the number of plates on the neck is usually six, although these may be reduced to four, while generally there are but six plates in the widest of the transverse rows on the back. The number of teeth in the upper jaw is seventeen or eighteen, against eighteen or nineteen in the lower. In colour the upper-parts are greenish black, speckled and streaked with yellow ; while the under-parts are greyish. In the much larger Mississippi alligator (A. mississippiensis), of which the dimensions exceed those of the great caiman, the front toes are webbed, there are but four plates on the neck, and there are always eight plates in the widest of the transverse rows of the back. There are nineteen or twenty teeth on each side of both jaws ; and in the adult the colour is dark green or blackish above, and yellowish below. The range of this species embraces the South-Eastern United States, from the Rio Grande to North Carolina. The third species (A. helois) is a small one, distinguished by the slight compression of the tail, which is scarcely crested. Our knowledge of the Chinese alligator (which was first made known to science in 1879) in the living state is mainly or entirely derived from specimens exhibited in the menageries of Europe ; while the accounts of the mode of life of the Missis- sippi species are by no means so full as is desirable. It appears, however, that the latter spends the greater part of its time in the water, where its main diet is formed by fish, although it will seize and drag such sheep, goats, dogs, deer, or horses, that, while drinking, come within reach of its terrible jaws. During flood-time, when many of the lowlands are under water, the alligators leave the rivers to feed on the fish which abound in the flooded districts ; returning to their old quarters with the subsidence of the inundations. To such flooded lowlands, writes Audubon, " in the early part of the autumn, when the heat of a southern sun has evaporated much of the water, the squatter, the hunter, the planter, all go in search of sport. The lakes then are about two feet deep, having a fine sandy bottom. . . . The long, ALLIGATORS. 19 narrow Indian canoe, kept to hunt these lakes, and taken into them during the freshet, is soon launched ; and the party seated in the bottom is paddled, or poled, to look for water-game. Then, on a sudden, hundreds of alligators are seen dispersed all over the lake ; their head and all the upper part of their body floating like a log, and in many instances so resembling one, that it requires to be accus- tomed to see them to know the distinction. Millions of the large wood-ibis are seen wading through the water, muddling it up, and striking deadly blows with Mississippi alligator (^ nat. size). their bills on the fish therein. ... It is then that you see and hear the alligator at his work ; each lake has a spot deeper than the rest, rendered so by these animals who work at it; and always situated at the lower end of the lake." By this means a supply of water is ensured ; and in these so-called alligators' holes the reptiles may be seen congregating in hundreds. " The fish, that are already dying by thousands through the insufferable heat and stench of the water, and the wounds of the different winged enemies constantly in pursuit of them, resort to the alligators' hole to receive refreshment, with a hope of finding security also, and follow down the little current flowing through the connecting sluices ; but no ! for, 20 CROCODILES. as the water recedes in the lake, they are here confined. The alligators thrash them, and devour them whenever they feel hungry, while the ibis destroys all that make towards the shore. By looking attentively on this spot, you plainly see the tails of the alligators moving to and fro, splashing, and now and then, when missing a fish, throwing it up in the air. The hunter marks one of the eyes of the largest alligators, and as the hair-trigger is touched the alligator dies. Should the ball strike one inch astray from the eye, the animal flounces, rolls over and over, beating furiously about him with his tail, frightening all his companions, who sink immediately ; whilst the fishes, like blades of burnished metal, leap in all directions out of the water, so terrified are they at this uproar." During the pairing-season, which takes place in the spring, the males resort to the land, and are but seldom seen ; while soon after the female deposits her hard white eggs, which are said at times to be upwards of one hundred in number. The nest in which the eggs are laid is generally placed among bushes or reeds, at a distance of fifty or sixty yards from the water's edge ; the eggs themselves being carefully covered with leaves and other vegetable matter. The heat engendered by the decomposition of the latter, aids in the hatching of the eggs ; and when the young appear, they are conducted to the water by the mother, who has all the time remained on guard near the nest. Double-Tusked In the middle and lower Tertiary deposits of both Europe and Alligators. the United States, the present group was represented by certain extinct alligators (Diplocynodon) characterised by the presence of a bony armour on the lower surface of the body, coupled with the circumstance that the fourth tooth of the lower jaw was generally received into a notch in the side of the skull, while the third lower tooth was as much enlarged as the fourth. Some of these double-tusked alligators had short snouts, like their existing allies ; but in one from the London Clay this part of the skull was much produced, as in manj'- crocodiles. stumpy A small and short-nosed crocodile (Osteolcemus tetraspis) from Crocodile. West Africa, in the neighbourhood of Sierra Leone, where it was discovered by Du Chaillu, presents much the same relationship to the true crocodiles as is held by the alligators to the caimans. Thus, while the arrange- ment of the teeth is similar to that obtaining in the true crocodiles, the nasal bones extend forwards to divide the cavity of the nostrils into two halves. Moreover, the upper eyelid is largely bony, while there are detached bony plates on the lower surface of the body, as well as on the throat. The shield of the neck is distinct from that of the back, and is composed of two or three pairs of plates, of which the anterior ones are very large ; while that of the back comprises seventeen transverse rows of plates, the broadest row including six of such plates. The ridges on the plates of the neck are strongly marked, but they become very obscure in the two middle rows of the back. The fore-toes have only rudimentary webs, although those of the hind-limbs are webbed for about half their length. With the exception of parts of the head, tail, and back, which are light brown with black markings, the coloration of the adult is uniform blackish brown. Young specimens are, however, yellowish brown, spotted with black above, and with bars of the same on the body and tail ; while the lower armour is black TRUE CROCODILES. 2T True Crocodiles. and yellow. Practically nothing is known as to the habits of this peculiar species, which are, however, probably very similar to those of its allies. The true crocodiles comprise rather less than a dozen species, ranging over Africa, Southern Asia, Northern Australia, and Tropical America. Having no bony armour on the lower surface of the body, they are distinguished from the caimans and alligators by the interlocking of the upper and lower teeth, and by the fourth lower tooth being usually received into a notch on the side of the upper jaw, so as to be partially visible when the mouth is closed, while the number of teeth varies from seventeen to nineteen on each side of the stumpy crocodile (^ nat. size). upper jaw, and fifteen in the lower. From the stumpy crocodile they are distin- guished by the aperture of the nostrils in the skull not being divided by the forward prolongation of the nasal bones. While some of the species resemble the alligators in their broad and short snouts, others have elongated, narrow snouts, approaching those of the garials ; but as there is an almost complete gradation from the one type to the other, this affords no ground for generic distinction, so that the most that can be done is to arrange them in groups. Commonly known to the natives of India as the magar, and misnamed alligator by Anglo-Indians, the Indian crocodile (Crocodilus palustris) is the best known representative of a group of four species which, in their broad and short snouts, make the nearest approach to the caimans and Indian CrocodUe. 22 CROCODILES, alligators. In all these the length of the snout does not exceed one and a halt' times its basal width ; the bony union between the two branches of the lower jaw does not extend behind the level of the fourth or fifth tooth; while on the palate the line of union between the anterior and main jawbones (premaxilke and maxillae) extends nearly straight across the skull, as shown in the figure on p. 2. The Indian crocodile has no bony ridges on the snout, while there are usually four longitudinal rows of bony plates on the back, and there are five teeth in each anterior upper jawbone or premaxilla. An allied species (G. robustus) from the interior of Madagascar, differs by having six longitudinal rows of plates on the back ; while the Cuban crocodile (0. rhombifer), of Central America, and a nearly related species (G. wioreleti), from Guatemala, are distinguished by having a more or less distinct oblique ridge in front of the eye. The habitat of the Indian crocodile includes India, Ceylon, Burma, and the Malay Peninsula and Islands ; its most westerly range being Sind and Baluchistan. Inhabiting rivers, lakes, and marshes, it appears to be an exclusively fresh-water species, never venturing into estuaries. As to the dimensions attained by this species there is some uncertainty, although it is probable that at the present day specimens seldom grow to the size that was reached before firearms were common. Nowadays from 12 to 14 feet appears to be a large size for this species, but a length of 18 feet has been recorded, while skulls in the Calcutta Museum would seem to indicate still larger individuals. A nearly allied extinct species has left its remains in the Siwalik Hills of Northern India. Swarming in most of the rivers and marshes of India, except where the current is too swift, the Indian crocodile is stated to be less ferocious than the species next mentioned, generally preying on the smaller animals, and not unfrequently dragging down a wounded or dead bird before the eyes of the gunner. When the waters they frequent become dried up, these crocodiles will either travel across country by night to another lake or river, or bury themselves in the mud. Estuarine Resembling its compatriot in its pale olive colour, conspicuously crocodile, spotted with black, the estuarine crocodile (C. porosus), of India and other regions, may be at once distinguished by its longer and more slender snout, as well as by the presence of only four teeth in each anterior jawbone or pre- maxilla of the adult. It belongs, indeed, to a group of four species, differing from the preceding assemblage in the length of the snout varying from rather more than one and a half to just over twice its basal width ; and also by the line of union between the anterior and main jawbones running in a V shape up the palate. The presence of a large ridge running down the skull in front of the eye serves to distinguish this species not only from all the other members of the group, but likewise from the Indian crocodile. The present species generally, if not invariably, inhabits the tidal portions of rivers, from whence it descends into the sea, where it has been observed floating at considerable distances from land. These estuarine and partially marine habits will readily account for the wide geographical distribution of this crocodile, which ranges from India to Australia. Unknown on the western coast of India, the estuarine crocodile is abundant in the lower courses of the rivers of Bengal and other parts of the eastern side of India, as well as in Ceylon and Burma, whence it extends eastwards to Southern China, TRUE CROCODILES. 23 Northern Australia, and the islands of the Solomon and Fiji groups. In point of size it probably surpasses all other species, one specimen being recorded which reached the enormous length of 33 feet In correspondence with its gigantic size, this crocodile appears to be one of the most formidable members of its kind, being exceedingly prone to attack human beings, more especially in the breeding-season, which takes place during June and July, when it is stated to attack such small boats as may cross its haunts. ESTUARINE CROCODILE (^ Dat. size Owing to its depredations, these crocodiles are cordially detested as well as feared by the natives of India, and at Dacca, on the north of the Bay of Bengal, crocodile-hunting is pursued as a profession. The following account of the pursuit of one of these monsters which had recently carried off a boy is abridged from a native newspaper. The hunter, having been summoned, moored his canoe hard by the place where the tragedy had taken place, it being well known that a crocodile which has been successful in securing a victim will generally remain for some days about the spot. Soon the crocodile was descried floating on the water, whereupon the hunter and assistant hid themselves in the canoe, while the son of the former entered the water, which he commenced to beat with his hands. Catching sight 24 CROCODILES. Nile Crocodile. of the boy, the crocodile prepared to dive towards him, upon which the boy took refuge in the canoe. In a moment or so the reptile rose to the surface at the expected spot, where he was "saluted with a couple of harpoons, one of which secured a firm hold. After a long chase, in which a number of the inhabitants of the village took part in boats, a second harpoon was safely planted in the head of the monster, who was finally dragged to shore. When opened, several gold and silver ornaments — the relics of earlier victims — were found in his stomach. In Ceylon, according to Sir J. E. Tennent, crocodiles are frequently captured by means of a hook and line, which are laid over-night in the water, and made fast, in the native fashion, by a bunch of fine cords. These cords becoming fixed between the interstices of the creature's teeth, are safe from being bitten through ; and in the morning the captive is dragged ashore and despatched. It may be added that, when thus captured, crocodiles emit a disagreeable musky smell, due to the secretion of a pair of glands in the lower jaw. Formerly inhabiting the Nile from its mouth to its source, the Nile crocodile (C. niloticus), from the invasion of its haunts by steam vessels and the introduction of rifles, has now well-nigh disappeared from Egypt, even as far back as the year 1870 being but rarely seen below Beni Hassan, and not common till above the second cataract. In the upper reaches of the Nile it still exists in its pristine numbers, whence its range extends southwards to the Cape and northwards to Senegal. The species also occurs in Madagascar, while it likewise still lingers in Syria, in the neighbourhood of the Zerka, or Crocodile River, near Csesarea. Distinguished from the estuarine crocodile by the absence of the ridge in front of each eye, this species differs from the other two members of the same group by the want of any ridge on the middle of the snout or forehead, so that its whole skull is comparatively smooth. In size it falls but little, if at all short of the estuarine crocodile ; although differing from the latter by the uniformly dark olive colour of the adult. As the habits of this crocodile do not differ in any important respects from those of the other members of the genus, they do not require any detailed notice, although a few words must be devoted to its cult by the ancient Egyptians, among whom it was known by the name of chamjJsa. By these remarkable people the crocodile was regarded as the symbol of sunrise — possibly, it has been suggested, on account of the brightness of its eye, or, perhaps, because that is the first part to appear when the creature emerges from the water. Among the places where the NILE CROCODILE. TRUE CROCODILES. 25 crocodile was specially reverenced were Thebes and the shores of Lake Moeris, as well as Ombi, near Syene. At Thebes a crocodile was reared from youth in the temple, where it was fed with sacred food, adorned with rings and bangles, and worshipped with divine honours ; while after death its mummified body was care- fully preserved in the catacombs, where hundreds of embalmed crocodiles are still to be found. Something analogous to this Egyptian veneration for the crocodile is to be met with in other countries. Leith-Adams tells us that the Indian crocodile is reclaimed by certain religious sects in India, being rendered so tame that it will leave its pond to feed out of its keeper's hand ; while Mrs. R. B. Lee relates that at Dix Cove, on the north-western coast of Africa, a pair of tame crocodiles were kept in a pond by priests, dressed in white garments, who fed their charges with snow-white fowls. In the Upper Nile the favourite haunts of the crocodiles are sandbanks, situated in parts of the river where the current is not too strong. There they may be seen at all hours of the day sleeping with widely opened mouths, in and out of which the black-backed plover (as mentioned on p. 475 of the preceding volume) walks with the utmost unconcern. According to Arab accounts, one and the same crocodile has been known to haunt a single sandbank throughout the term of a man's life ; thus leading to the conclusion that these creatures must enjoy a long term of existence, during the whole of which they continue, like other reptiles, to increase in size. In common with this feature of uninterrupted growth, all crocodiles are also distinguished by their remarkable tenacity of life ; the shots that prove instantaneously fatal being those that take effect either in the brain itself or in the spinal cord of the neck. It is true indeed, that a shot through the shoulder will ultimately cause death ; but it allows time for the animal to escape into the water, where its body immediately sinks. To reach the brain, the crocodile should be struck immediately behind the aperture of the ear. Although it is commonly supposed that the bony armour of these reptiles is bullet-proof, this is quite erroneous; if the plates are struck obliquely, the bullet will, however, frequently ricochet. A remarkable instance of boldness and ferocity displayed by a crocodile of this species is narrated by a correspondent of the Times during a journey to Mashonaland. On arriving one evening at the banks of the narrow but rocky Tokwi River, a man named Williams rode in with the intention of crossing. During the passage his horse was carried by the stream a few yards below the landing-place, and just as he reached the opposite bank he was seized by the leg by a crocodile, which dragged him from his horse into the stream. There the reptile let go its hold, upon which the man managed to crawl on to a small island. Immediately his companion rode in to his assistance, upon which another very large crocodile mounted up between him and his horse's neck, and then slipped back, making a dreadful wound on his side and in the horse's neck with its claws as it did so. The river seemed, indeed, to be absolutely swarming with crocodiles ; and it was with the greatest difficulty that the unfortunate man Williams, who ultimately died of his wounds, was brought to bank. The Siamese crocodile (C. siamensis), inhabiting Siam, Cambodia, Siam Crocodile. . ■■ . •■ , , and Java, may be distinguished from the preceding species by the 26 CROCODILES. presence of a longitudinal ridge on the skull between the eyes, although the snout is smooth. It agrees with the latter in having the anterior bony plates of the neck well developed, these being usually absent in the estuarine crocodile. Sharp-Nosed The last member of this group is the sharp-nosed crocodile Crocodile, (jj americanus) of Central America, which has a longer and sharper muzzle than any of the preceding, and is further characterised by the presence of sharp-nosed crocodile (■£„ nat. size). a distinct median ridge running down the snout. There are usually four large bony plates on the neck, forming a square, with a smaller pair on the sides of the front ones ; while the plates of the back are arranged in fifteen or sixteen trans- verse rows, and in either four or six longitudinal bands. In the fore-limb the second and third toes are but slightly webbed, while the outer toes of the hind- foot are united by larger webs. In coloration the adult is blackish olive above, and yellowish beneath; while the young are pale olive with black spots. In addition to being widely distributed in Central America and the adjacent regions, TRUE CROCODILES. 27 such as Ecuador, Colombia, Venezuela, and Florida, this crocodile is also met with in the West Indian Islands. Orinoco Nearly allied to the last, although with a still longer and more crocodile. slender snout, is the Orinoco crocodile (C. intermedins), which is referred by Mr. Boulenger to a third group, characterised by their very slender and garial-like snouts, of which the length is equal to at least twice the basal breadth ; and also by the bony union between the two branches of the lower jaw extending as far back as the sixth, seventh, or eighth tooth, instead of stopping short at the fifth. In this particular species the snout, which has no ridges, varies in length from twice to twice and a half the width at the base ; while the six bony plates on the neck are widely separated from those of the back, and are arranged in a square of four, with a pair on the sides. The colour is olive above and yellowish beneath, while in both this and the preceding species the length is about L3 feet. The Orinoco crocodile appears to be confined to the river from which it :akes its name and its affluents. The best accounts of the Orinoco and sharp- losed crocodile are by Humboldt, who states that these reptiles swarm on the Ipure, where they may often be seen in parties of eight or ten lying on the open ;vpace between the shore of the river and the forest. At the time of his journey he river was, however, still low, and consequently hundreds of crocodiles were ying concealed beneath the mud of the adjacent lowlands. In the stomach of one 1 hat was opened were found a half-digested fish and a granite pebble ; the latter ] laving probably been swallowed inadvertently while the animal was groping about in the mud in search of food. In spite of their comparatively slender jaws, these ( rocodiles frequently seize the natives while stooping to draw water from the river. A large portion of their prey is, however, afforded by the defenceless carpinchos, • vdiich are met with in droves of from fifty to sixty head, and fall victims to the j aguars on land and to the crocodiles in the water. In their young state — when ( nly from 7 to 8 inches in length — the crocodiles themselves are, however, devoured 1 »y vultures, who seize them on the shore or in the shallow water. It was curious, ( bserves Humboldt, to see the address with which the little reptiles defended ihemselves for a time against their aggressors. As soon as they perceived the ( nemy, they raised themselves on their fore-paws, bent their backs, and lifted up iheir heads, opening their wide jaws. They turned continually, though slowly, i owards their assailant to show him their teeth, which, even when the animal had 1 ut recently issued from the egg, were very long and sharp. Often, while the •< ttention of one of the young crocodiles was wholly engaged by one of the f ultures, another seized the favourable opportunity for an unforeseen attack, ] ouncing on the unfortunate reptile by the neck and bearing it off* in the air. The 1 necdote told by Humboldt of a native of Calabozo being awakened in the middle c £ the night by one of these crocodiles suddenly breaking through the mud of the i oor of his hut, beneath which it had retired for the dry season, is probably 1 imiliar to most of our readers. Long-Nosed Omitting notice of the small Johnston's crocodile (C. johnstoni), Crocodile. 0f North Australia, the last member of the genus is the curious long- 1 osed crocodile (C. cataphractus), of West Africa, which forms a kind of connecting 1 nk between the other true crocodiles and the garials. In this species the snout 28 CROCODILES. is more elongated and slender than in any of its congeners, its length not unfre- quently exceeding three times its basal width ; the bony union between the two branches of the lower jaw being likewise of unusual length. In form the snout is convex, and devoid of ridges ; while the region of the forehead is remarkable for its convexity. The great peculiarity about the species is, however, to be found in the arrangement of the bony plates on the neck, which form two longitudinal rows, and are partially if not completely continuous with those of the back ; a some- what similar arrangement existing in Johnston's crocodile. On the back the long-nosed crocodile (^ nat. size number of longitudinal rows of shields is six ; and the lower parts of the legs, as in many other crocodiles, are furnished with a jagged horny fringe. In colour the head is olive spotted with brown ; the back and tail have a brownish yellow ground-colour, with large black spots, while the yellowish white under-parts are marked with smaller white spots. In length this species reaches some 18 feet. The long-snouted crocodile is found in the rivers and marshes of West Africa, from Senegambia to the Gabun, and also occurs farther to the south in the Congo ; its native name being khinh. Not unfrequently found in company with the Nile crocodile, it inhabits the smaller streams and still waters of the interior, generally GARIALS. 29 taking up its position in a deep pool protected by an overhanging bank or rock, and thence sallying forth on its prey, which consists chiefly of fish, frogs, and aquatic reptiles. The eggs are laid on the bank, where, unlike those of most other members of the family, they are carefully covered with leaves and herbage. Shy and timid in its disposition, this crocodile is often captured by the natives for the sake of its flesh ; which, like that of many of its allies in other regions, is much esteemed as food. While very abundant in the fresh waters of the interior, this species likewise haunts the salt-water lagoons of the Guinea Coast; and in the delta of the Cameruns may be observed lying on the sandbanks bordering the mangrove swamps, from which, on the approach of a boat, it darts into the water with surprising celerity. There it often pulls down herons and such other aquatic birds as may be standing or swimming in the water, sailing up to them with the silence of a large fish, to which, when in the water, it presents a considerable resemblance. As in the estuarine and Nile crocodiles, in the adult of this species the second tooth in the fore jawbone, or premaxilla, disappears, leaving only four in place of the normal five on each side. With the very long and slender-snouted crocodile from Borneo, Schlegel's Garial. * to commonly known as Schlegel's garial (Rhynchosuchus schlegeli), we come to the first of two genera, each represented by a single existing Oriental species, which differ very remarkably from any of those yet noticed. In both these forms the snout is long and slender, with its teeth-bearing margins nearly straight, instead of being thrown into more or less well-marked festoons ; while the nasal bones never extend forwards to reach the aperture of the nostrils, from which they are separated by a considerable interval. Moreover, the bony union between the two branches of the lower jaw is of great length, extending at least as far back as the fifteenth tooth ; and including a bone which in the other crocodiles remains entirely separate from the symphysis. In neither do the teeth attain the large dimensions characteristic of many other members of the family. Schlegel's garial has the shorter snout of the two, its length not exceeding three and a half times its basal width ; but it is especially distinguished by the circumstance that the nasal bones extend forwards to articulate with the anterior jawbones, or premaxillse. The teeth are twenty or twenty-one in number on each side of the upper jaw, and eighteen or nineteen in the lower ; those on the sides of the latter being received in pits between the upper ones, and the first, fourth, and ninth lower teeth being enlarged. The bony plates on the neck and back form a continuous shield consisting of four longitudinal, and twenty -two transverse rows ; and while the fore-toes are webbed at the base, the outer ones of the hind-feet have larger webs. In colour, Schlegel's garial is olive above, with dark spots or bars ; while its length may be 12 or 14 feet. In habits this species is probably very similar to the Indian garial. It is important to notice that several fossil repre- sentatives of this genus occur in the Tertiary deposits of Europe, while it is not improbable that the genus is also represented in the underlying Cretaceous rocks. All this is exactly in harmony with what we should naturally have expected to be the case, seeing that Schlegel's garial, like the true garial, is evidently a very generalised member of the family. 3o CROCODILES. Garial, Probably owing to a clerical error on the part of its first describer the slender -snouted crocodile known in India by the vernacular name of garial, is almost always spoken of in Europe as the gavial, while its mis- spelt name has even been Latinised into Gavialis — an error which some writers persist in perpetuating. The garial (Garialis gangetica) is readily distinguished at a glance from all other crocodiles by the exceeding length and slenderness of i- ^ffld K( A\ V i wmmt lk l i gangetic garial (^ nat. size). its snout ; the length varying from more than five times the basal width in the young to rather more than three in the adult. This narrow snout gives to the reptile a decidedly curious appearance; and it is perhaps noteworthy that both the garial and the gangetic dolphin, which inhabit the same rivers, and probably feed on the same kind of food, have similarly elongated beak-like snouts, armed with very similar curved and slender conical teeth ; this resemblance being doubt- less due to adaptation to a similar mode of life. From Schlegel's garial, the present species is readily distinguished by the nasal bones being very short, and GARIALS. 3 1 consequently separated by a long interval from the anterior jawbones, or pre- maxillae ; while the teeth — twenty -seven to twenty-nine on each side of the upper, and twenty-five or twenty-six in the lower jaw — are all of nearly uniform size, and those of the lower jaw are not received into distinct pits. Moreover, the bony union between the two branches of the lower jaw extends backwards to the twenty-third or twenty-fourth tooth, whereas in the Bornean species it stops short at the fourteenth or fifteenth. At its extremity the long and narrow snout becomes much expanded ; and in the male this expanded extremity is surmounted by a hollow hump, in the centre of which are placed the nostrils. The bony plates of the neck form a shield continuous with that of the back, in which the number of longitudinal rows is four, while there are twenty-one or twenty-two transverse bands. Externally to the bony shields of the back there occurs on each side a row of soft plates, which are either smooth, or but slightly keeled. The toes are well webbed ; and the general colour of the adult is dark olive above ; the young being pale olive, with dark brown spots or bars. The garial has a somewhat curious geographical distribution, being restricted to the Indus, Ganges, and Bramaputra, with their larger affluents, together with the Mahanadi in Orissa, and the Koladyni River in Arakan. Together with certain tortoises mentioned later on, this reptile is one of the most ancient of living animals, its fossil remains occurring in the rocks of the Siwalik Hills in Northern India in association with those of mammals belonging to extinct species and genera. Attaining a length of fully 20 feet at the present day, and still larger dimensions during the Pliocene period, the garial subsists solely upon fish, for the capture of which its elongated narrow jaws, armed with numerous long, curved teeth, are admirably adapted. There appears, indeed, to be no well authenticated instance of these reptiles having attacked human beings or the larger mammals ; and it is perhaps owing to this harmless disposition that they are held sacred in many parts of India by the Hindus. In accordance with the nature of its prey, the garial seems to be more thoroughly aquatic in its habits than most of its allies ; the relatively long hind-limbs and the fully- webbed toes being features specially suited to aid in swimming. In the breeding-season the female garial lays about forty eggs in the sand of the river bank, these being deposited in two layers, and covered to a considerable depth with sand ; the two layers being probably laid on different days. The newly hatched young, which, from the great proportionate length of their snouts, present a most extraordinary appearance, are very active, and of a greyish brown colour, with five irregular dark oblique bands on the body, and nine on the tail. „ . „ . In addition to those of the existing species, the Siwalik Hills Extinct Garials. . . . , have yielded remains of several extinct garials, some of which attained gigantic dimensions ; while other species belonging to the living genus have been obtained from the middle Tertiary rocks of England. Possibly, also, certain fossil garials from the Cretaceous deposits of the United States should find a place in the same generic group. Other Cretaceous species are, however, remarkable for the presence of a vacuity in the skull in front of the eye-socket, in consequence of which they have been separated as a distinct genus, under the name of Thoracosaurust Mention must also be made of an enormous garial from the Siwalik Hills, known 32 CROCODILES. as Rhamphosuchus, which attained a length of some 50 or 60 feet, and had teeth as large as those of the biggest crocodile ; its upper teeth biting on the outer side of the lower ones, instead of interlocking with them, as in the living form. The Earlier Crocodiles. As already mentioned, all the existing crocodiles, together with the species from the Tertiary formations, constitute a single family, characterised by the vertebrae having a ball in front and a cup behind, and by the internal nostrils being situated at the hinder end of the skull ; as well as by the bony plates of the back being arranged in at least four longitudinal rows. Although a few species found in the topmost beds of the underlying Secondary formations approximate in some respects to the foregoing, the majority of the crocodiles from rocks as old or older than the Chalk differ very considerably from the existing types. In the first place, the bodies of their vertebras articulate with one another by slightly hollowed surfaces at both ends ; while, owing to the want of union between the hindmost bones of the palate beneath the nasal passages, the internal apertures of the nostrils are situated nearly in the middle of the skull. Then again, when a bony armour is present, the plates on the back are arranged in only two longitudinal rows ; while those on the lower surface of the body form two distinct shields. It is remarkable that among these extinct crocodiles some are met with having broad and short snouts like the modern alligators, while others have long and narrow snouts like the garials. In the Wealden and Purbeck rocks, underlying the Chalk, some of these crocodiles, such as the short-snouted Swanage crocodile (Goniopholis), resembled living types in having the socket of the eye communicating freely with the lower temporal fossa, although they were distinguished by the plates of the back articulating together by means of a peg-and-socket arrangement. In still older formations, such as the Lower Oolites and Lias, there were, however, many long-snouted crocodiles, such as the steneosaurs (Steneosawrus) and pelagosaurs (Pelagosaurus), in which the socket of the eye is divided from the lower temporal fossa by a bony bar, as shown in the figure on p. 13. Moreover, in these forms the upper temporal fossa (T in the figure cited) was larger than the socket of the eye ; whereas in all living forms the former is much the smaller of the two, and may even be obliterated. Another group of crocodiles, — the metriorhynchs (Metriorhynchus), — of the Oxford and Kimeridge Clays, were remarkable in having no bony armour at all, in which respect they were more specialised than any of their living cousins. In general, however, the earlier extinct crocodiles, as will be gathered from the foregoing remarks, were decidedly of a less specialised type than those of the present day ; and as a gradual transition can be traced in these respects from the oldest to the most recent, the group affords a very interesting instance of progressive evolution. In the very oldest of the secondary rocks, namely, the Trias, there occur, both in Europe and India, certain very remarkable long-snouted reptiles, known as Parasuchians, which appear in some respects intermediate between crocodiles and tuateras. Thus, while they resembled the former in the nature of their teeth, bony armour, ribs, and vertebras, they approximated to the latter in the structure of the skull, abdominal ribs, and probably of the collar-bones and interclavicle. DINOSAURS. Zi The Extinct Dinosaues. Order Dinosauria. Nearly allied to crocodiles are those remarkable extinct reptiles from the rocks of the Secondary period, which include amongst their number the most gigantic of all land animals, and likewise those members of the reptilian class which make the nearest approximation in their organisation to birds. During that epoch of the RESTORATION OP THE IGUANODON. earth's history in which the Chalk and underlying Oolitic rocks were deposited, when mammals were represented by a few small forms of lowly type, these strange reptiles were the dominant animals on land; some progressing in the ordinary lizard-like manner, while others stalked on their hind -limbs like birds. To give some idea of the enormous dimensions attained by some of these creatures, it may be mentioned that the thigh-bone of one species measures 64 inches, while the total vol. v. — 3 34 DINOSAURS. length of its skeleton is estimated to have been between 60 and 80 feet. On the other hand, some species were comparatively small, and not more than a couple of feet in length. Although the whole of these reptiles are markedly distinct from the crocodiles, yet they agree with them in the general characters of their skulls, vertebrae, and ribs ; but they differ so decidedly from one another that it is not easy to give a definition of the entire order. They are, indeed, divided into three well-marked groups, with so many differences between them that in the opinion of many they are entitled to rank as separate orders ; and it will, accord- ingly, be most convenient to treat these three groups seriatim. Lizard-Footed The most stupendous members of the order are included in a Group. group which may be conveniently designated lizard-footed dinosaurs, on account of their walking in the ordinary lizard-like manner, and in having five toes to the feet. The most striking peculiarity of this group is to be found in the LEFT-SIDE VIEW OF AN IMPERFECT VERTEBRA OF A lizard-footed dinosaur. (From the Quart. Journ, Geol. Soc, 1893.) INNER AND LATERAL VIEWS OF A TOOTH OF A HOPLOSAUR. circumstance that the vertebrae of the neck and back, as shown in the accompany- ing figure, had large cavities in their sides, which in the living state may have been filled either with cartilage or with air. These vertebrae resembled those of existing crocodiles, as described on p. 6, in having a ball at one end and a cup at the other ; but whereas in crocodiles the ball is at the hinder end of the body and the cup in front, in these dinosaurs precisely the reverse of this arrangement obtained. As regards their dentition, these reptiles had their teeth implanted in distinct sockets, like crocodiles ; but the teeth themselves, as shown in the accompanying figure, were of a peculiar spatulate shape, with the outer side convex and the inner concave. Agreeing in the general structure of their pelvis with crocodiles, these CARNIVOROUS GROUP. 35 INNER AND OUTER VIEWS OF A TOOTH OF . (From the Quart. Joum. Geol. Soc. . PELOROSAUR. 1893.) dinosaurs were distinguished therefrom by the circumstance that the bone known as the pubis (p in the figure on p. 3) enters into the composition of the cavity for the reception of the head of the thigh-bone. The limb -bones are solid throughout. From the nature of their teeth, which are often much worn by use, it may be inferred that these reptiles were vegetable feeders; and it is not improbable that they frequented the margins of lakes and rivers, where their inordinately long necks would enable them to browse with ease on the various aquatic plants. That they must have been very sluggish in their movements and stupid in their ideas is indicated by the wonderfully small propor- tionate size of their brains. These dinosaurs were common both in Europe and the United States, the larger forms having been described under the names of pelorosaurs (Pelorosaurus), atlantosaurs (Atlantosaurus), brontosaurs (Brontosaurus), and hoplosaurs (Hoplosaurus) ; among which the atlantosaurs appear to have been the most gigantic. They also occur in India, Argentina, and Madagascar. Carnivorous The carnivorous dinosaurs, of which the Group. megalosaur (Megalosaurus) is the best known example, differed from the preceding group in the form of their teeth, which were compressed and sickle-shaped, with sharp cutting, and frequently serrated edges. Their limb- bones also were hollow ; while their vertebrae were likewise hollow internally, but had no lateral cavities ; and the pelvis (figured on p. 3), although of the same general type as in the lizard-footed group, presented important points of distinction. In place of the short feet of the last-named group, the carnivorous dinosaurs had elongated foot - bones, terminating in sharp claws ; the number of functional toes in the hind-foot varying from four to three. That they habitually walked on the toes of their hind- limbs, and not (as was the case with the lizard-footed group) on the whole foot, is evident from the structure of this part of the skeleton, and from the circumstance that the fore-limbs were considerably smaller than the hinder pair, it may be inferred that progression was at least frequently accomplished by the aid of the latter alone. The close approximation of the huckle-bone of the ankle to the lower end of the tibia foreshadows the complete BONES OF THE FOOT OF A DINOSAUR. RIGHT HIND- CARNIVOROUS 36 D1N0SA URS, amalgamation which takes place between those bones in birds ; while in one remarkable American form the metatarsal bones of the foot were reduced to three in number, and had nearly the same relationship to one another and to the bones of the ankle as obtains in birds. While the megalosaur attained a height, when erect, of some 15 feet, the little Compsognathus, of the lithographic limestones of Bavaria, did not stand more than 2 feet ; and there were other equally diminutive forms, both in England and the United States, in which the whole backbone was so permeated by air-cavities as to be little more than a mere shell of bone. The Bird-Like The whole of the dinosaurs mentioned Group. above agree with one another in possessing a pelvis approximating to the crocodilian type ; that is to say, the pubis or anterior lower bone of this part of the skeleton is inclined down- wards and forwards, and thus diverges in the form of an inverted Ffrom the THE LEFT HUCKLE-BONE AND LOWER END OP TIBIA OP THE MEGALOSAUR. — After Gaudry. SKELETON OF THE CLAOSAUR, ONE OF THE BIRD-LIKE DINOSAURS (^ Hat. size).— After Marsh. backwardly and downwardly directed ischium, or posterior lower bone, as shown on the figure on p. 3. On the other hand, in the bird-like dinosaurs the main BIRD-LIKE GROUP. 37 OUTER AND LATERAL VIEWS OF A TOOTH OF THE IGUANODON. bar of the pubis is inclined backwards, parallel to the ischium, while it has a secondary plate projecting forwards. In this parallelism of the pubis and ischium these dinosaurs resemble birds (see the figure in Vol. III. p. 290), and birds alone ; and from this and other features it is pretty certain that the latter are derived from reptiles more or less closely allied to this or the preceding group of dinosaurs ; the resemblance in the one case being closest in the structure of the pelvis, and in the other of the hind-limb. All the bird-like dinosaurs are further characterised by the presence of a separate chin-bone (pd in the figure on p. 3) at the extremity of the lower jaw; by the absence of teeth from the front of both jaws ; by the teeth themselves approximat- ing more or less closely to the type of the one here represented, and by being fre- quently not implanted in distinct sockets ; and likewise by the vertebrae being com- pletely solid throughout. The typical representatives of this group are the well- known iguanodons, originally described on the evidence of teeth, from the Wealden rocks of England, but now known by entire skeletons from the corresponding deposits of Belgium, which are exhibited in the museum at Brussels. These reptiles, which were represented by allied forms in the United States, habitually walked on their three-toed hind-limbs, the largest individuals attaining a length of some 33 feet. They are characterised by the limb-bones being hollow, by the length of the metatarsal bones of the foot, by the first digit of the five-toed fore-limb being converted into a large conical spine, and also by the teeth being of the type of the one shown in the accompanying figure. Needless to say, animals with such teeth must have been purely vegetable feeders, as indeed were all the other members of this group. The hind - feet terminated in rather sharp claws, and there was no bony armour on the body. The iguanodons probably stalked about among the palm -forests of the Wealden period, on the leaves and fruit of which they may be presumed to have in great part subsisted. In these reptiles the large flattened and serrated teeth were arranged in each jaw in a single row, but in cer- tain smaller forms known as trachodons, which occur in the higher Cretaceous rocks of both Europe and North America, there were several rows of teeth in use at the same time, the edges of these teeth being so flattened and fitted to- gether that a pavement -like structure PAVEMENT-LIKE TEETH OF THE TRACHODON. — After Marsh. TERMINAL TOE-BONE OF AN ARMOURED dinosaur.— After Marsh. 38 DINOSAURS. resulted. These trachodons were all much inferior in size to the gigantic iguanodons. The American claosaur (Claosaurus), of which the skeleton is figured on p. 36, differs from the iguanodons in having the fore-paw of normal structure. Nearly allied to the iguanodons are the remarkable armoured and horned dinosaurs, which constitute a subgroup characterised by their solid limb-bones, the presence of some kind of bony armour, the short foot -bones, frequently terminating in hoof-like toes, and the habitually quadrupedal gait. Commencing in the British Lias, these extraordinary reptiles i-i !m continued throughout the Secondary period, and seem to have at- tained their maximum development at the close of the Cretaceous epoch in the United States. Of the armoured forms, the huge stegosaur of the English Oxford, and Kimeridge Clays, and the corresponding rocks of the United States, was characterised by the possession of large quad- rangular bones, which are believed to have been arranged in a vertical position down the middle of the back, while the tail was protected by some formidable spines, as shown in the greatly reduced restoration of the skeleton given on p. 4. Still more strange were the somewhat later horned dinosaurs (Ceratops, etc.), of which two views of the skull and a more reduced restoration of the skeleton are here given. In these extraordinary creatures the hinder part of the head was provided with a pair of bony horn- like projections, which were doubtless ensheathed during life with hollow horns, like those of oxen; and there was also a single horn of variable size on the nose. The skull was further remarkable for the expansion of its hinder extremity into a fan-like shield overhanging and protecting the vertebrae of the neck. Some idea of the huge dimensions attained by these dinosaurs will be conveyed by the UPPER AND SIDE VIEWS OF THE SKULL OP A HORNED DINOSAUR. a, nostrils ; /, brain ; h, horn ; n , nasal bones ; p, chin-bone ; r, extremity of upper jaw. — After Marsh. FLYING DRAGONS. 39 statement that an immature skull of one of the species measures upwards of 6 feet, while fully adult ones must have been considerably larger. The extraordinarily small size of the brain of these creatures is indicated in the lower figure of the skull. Externally the bodies of these dinosaurs were protected by granules and plates of bones, which, like those of crocodiles, were probably overlain with horny shields. It has yet to be mentioned that in the horned dinosaurs, as shown in the figure of the skeleton, the posterior bar of the pubis has disappeared, and only the restoration of the skeleton of a horned dinosaur. front branch remains, thus pd, chin-bone. Other letters as in the figure on p. 4.— After Marsh. causing the whole pelvis to simulate that of the carnivorous group, to which it has no real resemblance. We have yet to learn the reason why, at the close of the Secondary period, these mighty dinosaurs, together with the flying dragons which at the same time tenanted the air, and the fish-lizards and plesiosaurs which peopled the sea, should, one and all, disappear — and that apparently suddenly — to make way for mammals and birds, which henceforth became the lords of creation. Flying Dragons, or Pterodactyles. Order Ornithosauria. At the present day bats and birds are the only Vertebrates endued with the power of true flight, but during the Secondary period, when the former were unknown and the latter but poorly represented, the place of both was taken by the flying dragons, or, as they are called, from the structure of their wings, Pterodactyles. While agreeing with crocodiles in the essential structure of their skulls and in their two-headed ribs, these curious reptiles have the other portions of their skeleton more or less specially modified for the purposes of flight. In the relatively large size of the brain — which is doubtless essential for a flying animal — and general bird-like form of the skull, as well as in the keeled breast-bone and general form of the collar-bones (although these are not welded together into a furcula), the pterodactyles present a curious similarity to birds. Misled by these resemblances, some anatomists have, indeed, been induced to consider that the two groups are nearly related, although a more mistaken notion never existed. Such resemblances as do exist between the two groups are due, indeed, to that parallelism in development to which we have already had occasion to call atten- tion as existing between totally different groups of animals whose mode of life is similar. The most distinctive feature of the pterodactyles is to be found in the modifications of the bones of the fore-limbs for the purpose of supporting a wing, which took the form of a membranous expansion of skin analogous to that con- 40 FLYING DRAGONS. stituting the wings of bats. This wing was mainly supported by the great elongation of the bones of the fifth digit or finger of the fore-limb, as shown in the accompanying figure of the skeleton, and likewise in the restored representation of one of these reptiles. The membrane thus supported seems to have extended backwards along the sides of the body to include the upper portions of the legs, between which it was extended to embrace the base of the tail in those forms in which the latter appendage was fully developed. Moreover, in the long -tailed species, the extremity of the tail itself was provided with a racket- shaped expansion of membrane, which may have served the purpose of a rudder in flight. If it be asked how the presence of such membranes is known, it may be answered that in many of the specimens of these reptiles en- tombed in the fine-grained litho- graphic limestones of Bavaria the actual impressions of these membranes have been preserved. The elongated fifth finger of the wing had no claw at the extremity, although the three middle fingers w^ere thus pro- vided. With regard to the first finger, or the one corresponding to the human thumb, this may have been represented by the small splint - like bone seen The creature is lying on its back, with the head bent to the left depending from the wrist in the side, a indicates the left pubic bone ; the haunch-bone, or ilium, n j 1 i i. m-L i • i being shown on the opposite side. %Ured skeleton. The hmd- limbs present no special peculiar- ities, but, as most of the bones of the skeleton were hollow and permeated by air, like those of birds, we may infer that the lungs were probably also constructed after the avian fashion. The vertebrae of the neck resembled those of living crocodiles in having a ball at the hinder end of the body and a cup in front. In general conformation the skull was remarkably bird-like, the snout being produced into a beak, which in some cases was provided with teeth, while in others, as shown in the figure on p. 5, it was toothless, and probably ensheathed during life with horn. Bird-like features are likewise shown by the large size of the brain-case, of which the component bones were fused together, and also by the union of the extremities of the two branches of the lower jaw. Pterodactyles flourished during the greater part of the Secondary period, dating from the epoch of the Lias, and continuing to the close of the one during which the SKELETON OF A ITERODACTYLE. FLYING DRAGONS. 41 Chalk was deposited. They are represented by several well-marked types, which may be arranged under three family groups. Of these the most specialised forms are the toothless pterodactyles, or pteranodonts, from the Cretaceous rocks of North America ; some of these toothless members of the order far exceeded any flying bird in point of size ; the estimated span of wing in the largest species being upwards of five-and-twenty feet. This group may be distinguished not only by the total absence of teeth, but likewise by the great backward extension of the hinder extremity of the skull. In the typical pterodactyles (Pterodactylus. etc.) the jaws were provided with restoration op a long-tailed pterodactyle {\ nat. size). — After Marsh. teeth, — which may, however, have been very small in size and few in number, — while the skull, as shown in the figure of the skeleton on p. 40, was not produced backwardly, and the tail was reduced to a rudiment. The members of this group, which are common in the Oolitic rocks of the Continent, vary in size from the dimensions of a sparrow to those of an eagle. Lastly, we have the long -tailed pterodactyles (Rhamphorhynchus, etc.), which are likewise of Oolitic and Liassic age, and are at once distinguished, as shown in the restoration, from the members of the preceding group by the fully developed tail. These long-tailed species are evidently the most generalised members of the order ; and in the retention of the tail in the generalised group, and its loss in the more specialised one, the reader will hot fail to notice an exact parallelism between ordinary bats and the more highly-developed fruit-bats. CHAPTER III. Tortoises, Turtles, and Plesiosatjrs, — Orders Chelonia and Sauropterygia. Among all existing reptiles the most easily defined are those commonly known as tortoises and turtles, and technically as Chelonians, since the presence of a more or less fully developed bony shell investing the body, and containing within it the upper portions of the limbs, at once separates them from all other members of the class. Indeed, so utterly strange is the conformation of these extraordinary UPPER SHELL OF THE CHAIBASSA TERRAPIN, AND A FOSSIL SPECIMEN OF THE SAME IN WHICH THE HORNY SHIELDS ARE WANTING. reptiles, that if they were met with only in the fossil state they would inevitably be regarded as among the most marvellous of all creatures. Here however, as elsewhere, the time-honoured proverb holds good, and our very familiarity from childhood with the common European land - tortoise undoubtedly tends to render us inappreciative of the marvellous bodily conformation of this group of reptiles. Although the presence of a bony shell is of itself sufficient to distinguish the GENERAL CHARACTERISTICS. 43 group from other living reptiles, it is necessary to add somewhat to this in order to give a comprehensive definition. As regards the skull, this resembles that of the crocodiles, in that the quadrate-bone, with which the lower jaw articulates, is firmly wedged in among the adjacent bones, to which its relations are, however, somewhat different. Unlike all crocodiles the jaws are, however, entirely devoid of teeth, and are encased with horn, so as to form a cutting beak, which is invari- ably short. A further peculiarity in the skull of a tortoise is to be found in the presence of a greatly developed median spine (sup) projecting backwards from the hinder region ; exter- nally to which are a pair of shorter processes. In other respects, the skull is extremely variable, the sockets of the eyes being sometimes, as in the figure on p. 47, surrounded by bone, while in other cases they are open behind. Sometimes, moreover, the bony roof behind the eye-socket in the figure on p. 47 may be prolonged backwards so as to cover the whole of the region marked par in the annexed figure. There is an equal amount of variation in regard to the position of the nostrils, which sometimes open on the palate close behind the beak, while they may be situated, as in living crocodiles, close to the hinder extremity of the skull. A most important feature in the structure of these animals is to be found in the circumstance that the ribs have but a single head apiece, and that the more anterior ones articulate at the junction between two of the vertebrae, so that one portion of the head is applied to one vertebra and the other portion to the adjacent vertebra. This forms an important distinction from the whole of the orders treated in the preceding chapter, in all of which the anterior ribs are provided with two heads, both of which articulate to the sides of one and the same vertebra. Passing on to the consideration of the bony shell, we find this to consist of an upper portion or carapace, shown in the figure at the commencement of the chapter, and of an inferior portion, covering the lower aspect of the body, which is termed the plastron. When this shell attains its fullest development, the upper and lower moieties are completely connected together, as shown in the accompanying figure of the skeleton of a land -tortoise; but in certain groups the two remain more or less separate, and in some cases the lower shell is but very slightly developed. Moreover, while the carapace is generally immovably welded to the vertebrae of the back and the ribs, in the so-called leathery turtle it is separate from both. In its fullest developed form, the shell consists of a series of bones articulating with one another at their edges by finely denticulated sutures, and thus forming a continuous whole, capable of increasing in size by growth at the edges of its component elements. In the carapace, the bones forming the middle of the back are formed by expansions growing from the spines of the vertebrae, while the large lateral plates grow upon the ribs, from which they are inseparable. Within the cavity thus formed are placed the bones of the shoulder and pelvis, to which are UPPER VIEW OP THE SKULL OF THE SOFT-TORTOISE OF THE GANGES. 44 TORTOISES AND TURTLES, respectively articulated the arm-bone and thigh-bone, so that, as shown in the figure of the skeleton, these bones actually come within the ribs, instead of being external to them, as in all other living animals. At the fore and hinder extrem- ities of the shell are left large apertures, through which are protruded the head and neck, the fore and hind-limbs, and the tail. A large number of tortoises are able to retract both the head, limbs, and tail within the margins of the shell, the apertures of which are then filled up ; such portions of the head and limbs as are exposed being protected by horny shields. With the exception of the marine leathery SKELETON OF TORTOISE IN LONGITUDINAL SECTION. tUTtlCfl ailO. tlie IreSU- water soft-tortoises, in which it is invested merely with a continuous leathery skin, the shell of Chelonians is covered with a number of horny plates, which, in the adult state at least, are in contact with one another by their edges. As these horny shields are very important in determining the different species of tortoises, it is essential to enter in some detail into their mode of arrangement, and the names by which they are known. In the carapace of any ordinary tortoise, such as the one represented in the left-hand figure at the head of the chapter, we shall find that the middle line of the back, exclusive of the margins, is occupied by a single row of large polygonal shields, symmetrical in themselves ; these shields, which are marked v in the accompanying diagram, being known as the vertebrals. On either side of this median series is another row of shields c, which are not symmetrical in themselves, and are termed costals. The extreme margins of the carapace are formed by a large series of much smaller shields, of which the anterior unpaired one (nu) is termed the nuchal, and the posterior (ca), which may be either single or double, the caudal. Between the nuchal and the caudal are a series, generally eleven in number on each side, designated marginals (m). These same marginal shields, being angulated, pass over the edges of the middle portion of the shell, and thus cover the sides of the middle of the plastron, or lower shell, as shown in the right- hand figure of the accompanying diagram. The shields of the plastron proper are generally arranged in pairs, which may be termed, commencing anteriorly, gulars (gu), humerals (hu), pectorals (pc), abdominals {ah), femorals (fe), and anals (an). In some cases, as will be illustrated in the sequel, the two gulars may, however, be separated by a single intergular; while, as in the accompanying diagram, there is frequently an inguinal shield immediately in advance of each notch for the hind-limbs. This disposes of the external horny shields ; but a few words are necessary with regard to the bony elements constituting the shell of a tortoise. On stripping off these horny shields from the carapace of a tortoise, the underlying solid shell, GENERAL CHARACTERISTICS. 45 as shown in the right-hand figure at the head of the chapter, will be seen to be marked by a series of channels corresponding to the borders of these same shields. If the shell be not that of a very aged animal, there will be seen in addition a number of finely jagged sutures, marking the divisions between the component bones ; and it will be noticed that in their plan of arrangement, although not in number, size, or shape, these underlying bones correspond very closely with the overlying horny shields. Thus, in the middle line of the carapace we have a series of polygonal plates, symmetrical in themselves, and attached to the summits of the vertebrae, which are known as neurals ; these being clearly indicated in the figure referred to. In front, the series is completed by a large nuchal plate, having no connection with the backbone, while behind it terminates in one or two pygals, ruL DIAGRAM OP THE HORNY PLATES ON A SHELL OF A FRESH-WATER TORTOISE.— After Gtintlier. which are likewise perfectly distinct from the vertebrae. Externally to the neurals are placed on either side the eight costal plates, so named from being attached to the ribs ; the inner halves of these plates being alone visible in the shell figured at the head of the chapter, which belonged to a rather aged animal. Finally, the edges of the carapace are formed by the marginal plates, which, like the horny shields similarly named, are angulated, and form the lateral borders of the middle portion of the plastron. In the plastron itself, we find its anterior portion formed by a pair of plates, known as the epiplastrals, corresponding to the collar-bones, or clavicles, of other Vertebrates ; while between or behind these is a single unpaired entoplastral element, which may be either dagger-shaped or rhomboidal, and which represents the interclavicle of less specially modified reptiles. The remainder of the plastron is formed by three pairs of plates, respectively known as the hyo, hypo, and xiphiplastrals, of which the latter or hindmost are generally more or less deeply notched or forked. These three elements appear to correspond to the so- called abdominal ribs of crocodiles ; and it will thus be evident that Chelonians have 46 TORTOISES AND TURTLES. no representative of the breast-bone, or sternum, which is so commonly present in other groups of Vertebrates. As regards their limbs, the members of this order present a great amount of variation, some of them, like the land-tortoises, having the feet adapted for walking, while in the turtles the entire limbs are modified into paddles for swimming. In some cases, each of the five toes may be furnished with strong, curved claws, but in others, like the soft-tortoises, only three are thus armed. As a general rule, the number of joints in the toes of the fore-limb, counting from within outwards, is 2, 3, 3, 3, 3, while in the hind-limb they are more generally 2, 3, 3, 3, 2, although in a few species the number is the same as in the fore-limb. In both limbs the number of these joints may, however, be reduced, but, except among the soft- tortoises, they are never augmented. Very generally, the surfaces of the limbs, especially the anterior ones of the front pair, are protected by horny plates of variable size, which, among the land-tortoises, may be underlaid by nodules of bone. In habits the members of the order display as much diversity as in structure ; some being carnivorous and others herbivorous, while some are marine, others fresh- water, and others, again, more or less exclusively inhabitants of dry land. All, however, are fond of water, and even the most strictly terrestrial species can, we believe, swim. With the exception of the turtles, the eggs are hard-shelled ; and these are in all cases deposited on land, the turtles resorting to the shore at certain seasons for this purpose. As regards distribution, tortoises are especially characteristic of the warmer parts of the globe, only two species inhabiting Europe and these confined to the more southern parts of the Continent. The various groups and families are, however, by no means equally distributed over the different regions of the globe. The side-necked tortoises, for instance, are now exclusively confined to the Southern Hemisphere, and in Australia are the only representatives of the order; whereas the S-necked group attains its greatest development in the opposite half of the world, although represented in many countries lying to the south of the Equator. The soft river-tortoises, again, are confined to the waters of Asia, Africa, and North America, being totally unknown both in South America and in Australasia. Giant land-tortoises within comparatively recent times have been confined to what are known as oceanic islands, although they formerly occurred on most of the large continents ; while the smaller members of the same genus are far more numerous in South Africa than they are in Asia. Geologically, the order is a very ancient one, being represented throughout the whole of the Secondary period, and thus commencing at a date when true crocodiles are not known to have come into existence. According to our own views of their mutual relationships, the Chelonians may be divided into three main groups, or suborders, which may be severally designated S-necked tortoises (including the turtles), side-necked tortoises, and soft-tortoises. Some writers would, however, remove from the first group the so-called leathery turtle, to make it the type of a group equal in value to the whole of the other three, which are thus collectively brigaded under a common title. Adopting the former arrangement, we commence our survey of the various members of the order with LAND- TOR TOISES. 47 The Land-Tortoises and Terrapins. Family Testudinid^e. The land-tortoises, together with the greater number of the fresh -water tortoises, or terrapins, of the Northern Hemisphere, as well as their southern allies, collectively constitute one of several families belonging to the first great group of the order. From the circumstance that all its members are so constructed as to be able to withdraw their heads within the margins of the shell by a bending of the neck in an S-like manner in a vertical plane, the group may be conveniently designated S-necked tortoises ; their scientific designation being Cryptodira. Since, how- ever, the soft-tortoises likewise retract their heads in a similar manner, it is obvious that this character alone will not suffice to define the group, and it must accordingly be supplemented by others. Although the degree of ossifi- cation of the shell is very variable in the group, the carapace and plastron being in some cases welded into a complete box, and in other instances separate, yet there is invariably a complete series of marginal bones, con- nected with the ribs ; the . presence of the full series of marginals, together with the S-like retraction of the neck, being sufficient to distinguish the group. A peculiarity in which the members of the group differ from those of the next one, is to be found in the circumstance that the bones of the pelvis remain throughout life unconnected with the plastron ; while in the greater number of cases THB LEFT HALF 0F THB PLAS- • i 1 ii i . ,, • r> • TRON OF THE CHAIBASSA the latter, as shown in the accompanying figure, comprises terrapin. only six pairs of horny shields, their being no intergular shield between the first pair, or gulars. The skull is characterised by the tympanic ring (t in the accompanying figure) having a notch in its hinder border, and also by the condyle on its quadrate - bone fitting into a hollow at the hinder end of the lower jaw. This S-necked group includes the marine turtles, and all the tortoises of the Northern Hemisphere, with the exception of the soft river- tortoises, and thus comprises by far the greater number of the living represent- atives of the entire order. Although well represented in Africa and South America, the group is quite unknown in Australia. The land-tortoises and terrapins of the family Testudinidce have the shell well developed and of a more or less ovoid shape ; the plastron being connected with the carapace either by a straight articulation or by means of sutures, while SIDE VIEW OF THE SKULL OF A LAND-TORTOISE, WITH THE LOWER JAW REMOVED. 48 TORTOISES AND TURTLES. it never has. an intergular shield in front. The limbs are adapted more or less completely for walking, and are never modified into paddles ; while the head is capable of complete retraction within the margins of the shell. A very important structural feature in the shell is that the nuchal, or unpaired median bone in the front of the carapace, does not send back processes underlying the marginal bones of the same ; while in the tail each vertebra has a cup in front of its body or lower portion, and a ball behind. None of the members of the family are marine,, but while some are inhabitants of the land, others are more or less exclusively dwellers in fresh water. There are, moreover, equally important differences in regard to their food, all the land forms being herbivorous, while of those frequent- ing the water some subsist on vegetable, and others on animal substances. . . „ . By far the most numerously represented genus of the whole t q tiq .Tort m^ip^ v x o family is the one including the true or land -tortoises, of which there are rather more than forty existing species (counting a few that have been exterminated within the historic period). These tortoises, of which a few are more or less aquatic in their habits, have the upper and lower portions of the shell completely welded together, the former being frequently very convex and much vaulted; while the top of the head is covered with large horny shields. The limbs, which are entirely adapted for walking, are of a club- like form, and are covered with large horny scales or tubercles; their toes being unwebbed and furnished with strong, claw-like nails. The tail is always short, its proportionate length not being greater in the young than in the adult. More important characters are, however, furnished by the bony shell and skull, to observe the former of which it is of course necessary that the horny shields should be stripped off. In a shell thus treated it will be seen that the unpaired median neural bones of the carapace are relatively short and wide, and so arranged that a four-sided one is interposed between two that are octagonal, although in some cases they are mostly hexagonal ; while the costal or lateral plates are alternately narrow above and broad below. Moreover, the line dividing the costal horny shields from the marginals usually corresponds with the suture between the corresponding bones of the carapace, whereas in the other members of the family one is above the other ; while a further peculiarity of most species of the genus is that there is but a single caudal horny plate at the hinder end of the carapace. In the skull the palate is provided with one or two ridges on each side ; while the hinder aperture of the nostrils is situated on the line of the eyes. It may be mentioned here that, as in the majority of the representatives of the order, the form of the shell differs considerably in the two sexes ; the male having the central region of the plastron deeply concave, while in the females it is flat or slightly convex. True tortoises are distributed over Southern Europe and Asia, the whole of Africa, the southern portions of North America, and South America (inclusive of the Galapagos Islands). They are strictly herbivorous in their diet ; and certain species, now confined to oceanic islands, attain gigantic dimensions, and are by far the largest representatives of the family. The species' inhabiting colder regions hibernate during the inclement season by burrowing in the ground, whereas those found in more genial climates are active throughout the year. All the species LAND- TOR TOISES. 49 appear to be diurnal in their habits, and although they are all fond of water, the common European species always withdraws into its shell at the slightest shower. These reptiles will live to an enormous age, which, in some instances at least, may be reckoned by centuries. According to the classification adopted by Mr. Boulenger, the species of this extensive genus may be arranged under seven groups, of which we proceed to notice representative species. The land-tortoises of North America include three species, of which one of the best known is the Florida tortoise (Testudo poly- phemus), inhabiting the South-Eastern United States. All these species may be Florida Tortoise. BRAZILIAN TORTOISE (| liat. size). easily recognised by the anterior extremity of the palate of the skull having a median longitudinal ridge, instead of the deep pit characterising all other members of the genus. In the Florida tortoise, as well as in the allied Agassiz's tortoise {T. agassizi), the length of the shell is more than twice its height, while the beak is not hooked, and the fore-limb is broadest at its extremity. On the other hand, in Berlandier's tortoise (T. berlandieri), from Mexico and Texas, the shell is proportionately shorter, the beak is hooked, and the fore-limb widest at the elbow. These species are all of small size, not exceeding 10 inches in length. Brazilian The Brazilian species (T. tabidata), figured above, represents a Tortoise. group by itself, of which the distinctive characters are as follows. The carapace is much elongated and somewhat depressed, with its margins not vot. v. — 4 50 TORTOISES AND TURTLES. everted ; its general colour being dark brown or black, with a yellowish centre to each of the shields on the back. The nuchal shield of the carapace is wanting ; while in the plastron the gular shields, although well developed, are prolonged anteriorly into hem-like processes. The head and limbs are marked with orange or red spots, on a dark ground. This handsome tortoise, which attains a length of nearly 22 inches, is an inhabitant of tropical South America, to the east of the Andes, and also of the Windward Islands, ascending to an elevation of about two thousand feet. In many wooded districts it appears to be very abundant, feeding not only on leaves and grasses, but likewise on the fallen fruit which is to be met with in great quantities. In the hot season it constructs a nest of dry leaves, wherein are deposited its eggs, which may be a dozen or two in number. When first hatched, the young are of a uniform yellowish brown colour, with their shells still soft. The young, and to a less degree the adults, have, according to the Prince of Wied, numerous enemies. Against the puma and jaguar the stout shell of even the adult seems to be no defence, since, according to native reports, those animals, on finding one of these tortoises, will set it up on end and scoop out the flesh with their paws ; while from the occurrence of broken shells in the forest it would seem that in some cases they are actually able to tear the plastron away from the carapace. As the flesh is devoid of smell, it is likewise eagerly sought after by both Indians and Portuguese, who are in the habit of keeping these tortoises — known in Brazil by the name of schabuti — in stews, where they are fattened for the table. They are also allowed to run about the houses, where they are fed chiefly on plantains, Burmese The four species belonging to the third group, of which the Brown Tortoise. Burmese brown tortoise (T. emys) is an example, are characterised by the presence of some very large conical, bony, spur-like tubercles on the lower portion of the hind-leg, and the circumstance that the length of the union in the middle line of the anal shields of the plastron is considerably less than that of the abdominal shields ; the colour of the carapace in the adult being either uniform brownish, or yellowish brown closely spotted with black. The Burmese brown tortoise, which attains a length of 18 inches, while agreeing with the species above noticed in the possession of a nuchal shield on the front of the carapace, differs in that the caudal shield at the hinder extremity of the same is divided, as in the terrapins. The shell of this species is much depressed, with the anterior and posterior borders of the carapace serrated ; the adult being dark brown, or blackish in colour, while in the young the carapace is yellowish brown, with dark brown markings. In addition to the spur-like tubercles on the back of the heel, the whole of the front of the fore-limb is overlain with imbricating bony tubercles, arranged in four or five longitudinal rows, and there are some conical ones on the back of the thigh, as well as others on the lower surface of the hind-foot. This species is an inhabitant of Assam, Burma, Siam, the Malay Peninsula, and Sumatra, where it frequents moist wooded districts, and is believed to be largely aquatic in its habits. The association of a divided caudal shield., with habits reputed to resemble those of the terrapins, is somewhat noteworthy. In the other three members of this group the nuchal shield is wanting, and the caudal single. Of these, the Argentine tortoise (T. argentina) of South LAND- TOR TOISES. 5 1 America, and the spurred tortoise (T. calcarata) of Africa, are characterised by their flattened and uniformly brownish-coloured carapaces. On the other hand, the handsome leopard-tortoise (T. pardalis) of Southern Africa, has the carapace highly vaulted, and closely spotted with black upon a yellowish brown ground ; its anterior margin being very deeply notched. SIDE VIEW OF SHELL OF BURMESE BROWN TORTOISE. (From Giinther, Proc. Zool. Soc., 1882.) The fourth group comprises about ten very beautifully coloured Elegant Tortoise. for r j » , . , small, or medium-sized, tortoises, the great majority of which are confined to South Africa, although the species here figured (T. elegans) is an inhabitant of India and Ceylon. All these species are easily recognised by the carapace being extremely convex, and either black in colour, with yellow lines radiating from the centre of each of the shields of the back, or yellow, or brownish, marked with radiating black lines. Frequently, moreover, the shields of the back are swollen, so as to form more or less prominent bosses. The Indian species, together with an allied one (T. platynota), from Burma, is distinguished from all the other members of the group by the absence of the nuchal shield at the front of the carapace. Of the other eight species no less than seven are South African, while the radiated tortoise (T. radiata) is from Madagascar; one of the best known members of the group being the common geometric tortoise (T. geometrica) of the Cape, which attains a length of some 5£ inches. In the eyed tortoise (T. oculifera) the pectoral shields of the plastron may not meet in the middle line, as is the case in some individuals of the Burmese brown tortoise. While the elegant and geometric tortoise have the carapace black, with narrow yellow rays, in the eyed tortoise the markings take the form of brownish yellow and dark brown rays of nearly equal width. An admirable account of the habits of the elegant tortoise is given by Capt. T. Hutton, from which the following extracts are made. These tortoises are fairly common in dry, hilly districts, where they inhabit the high grass-jungles at the foot of the hills. Nevertheless, they are by no means easy to find, owing to their colour and appearance harmonising so closely with the rocky ground, and from their habit of remaining in concealment beneath shrubs or tufts of grass during the heat of the day. They are tracked by the Bhils of Meywar to their hiding- 52 TORTOISES AND TURTLES. places by following the trail of their footsteps in the dry sand ; the same method being employed by some of the wild tribes of South Africa in the case of the allied species inhabiting that continent. In the rainy season the elegant tortoise is, however, extremely active, and wanders about in search of food at all hours of the day. At the approach of the cold weather these reptiles select a sheltered spot, where they conceal themselves by thrusting their shells into thick tufts of bushes or shrubs, in order to be better protected from the cold. There they remain in a kind of lethargic, although not truly torpid, state, till the hot season, when they issue out to feed only after sunset and in the early morning. Specimens kept in captivity were observed to be very fond of plunging into water ELEGANT TORTOISE (J Iiat. size). during the hot season, where they would remain for half an hour at a time. They also drank large quanties of water at this period of the year, which they took by thrusting in their heads and swallowing in a series of gulps. About November the female lays her eggs in a shallow pit excavated by herself. One of the aforesaid captive specimens in the course of about two hours " succeeded in making a hole six inches in depth and four inches in diameter; in this she immediately deposited her eggs, four in number, filling up the hole again with the mud she had previously scraped out, and then treading it well in, and stamping upon it with her hind-feet alternately until it was filled to the surface, when she bent it down with the whole weight of her body, raising herself behind as high as GIANT TORTOISES OF THE GALAPAGOS ISLANDS. LAND- TOR TOISES. 55 she could stretch her legs, and suddenly withdrawing them, allowing herself to drop heavily on the earth, by which means it was speedily beaten flat ; and so smooth and natural did it appear that, had I not detected her in the performance of her task, I should certainly never have noticed the spot where she had deposited her eggs. She did not immediately leave the place after finishing her work, but remained inactive, as if recovering from her fatigues." In disposition these tortoises are decidedly pugnacious, this being especially the case with the males. These combats seemed to be chiefly trials of strength, " one male confronting the other, with the hind and fore-legs drawn into the shell, and the hind-feet planted firmly on the ground, and in this manner striving against each other until one or both became fatigued. This was done chiefly when they wanted to pass each other in any narrow space ; and sometimes if the one could succeed in placing his shell a little beneath the other, he tilted him over on his back, from which he had great difficulty in recovering himself; and I have frequently found them sprawling thus, making desperate efforts with head and feet to throw themselves back to their natural position, which they were unable to effect unless the ground chanced to be very uneven, so as to assist them." During the Pliocene, or later division of the Tertiary period, Giant Tortoises. . *» ■-. , gigantic land-tortoises were, as attested by their petrified remains, widely distributed over the continents of the world ; species having been obtained from India, France, and North and South America. The largest of these was the well-known atlas tortoise (T. atlas) from the Siwalik Hills of Northern India, in which the length of the shell was about 6 feet ; the species itself being apparently allied to the existing Burmese brown tortoise already referred to. Probably more or less abundant during the epoch in question, with the advent of the ensuing Pleistocene epoch giant tortoises seem to have disappeared entirely from the continental areas, to survive on certain oceanic islands where they were free from the competition of large animals of higher organisation. Some of these insular species, like those of Madagascar and Malta, did not apparently survive the Pleistocene epoch ; while in other regions they flourished and multiplied till the fell presence of man led to their partial or total extermination. At the present day the few survivors of these monstrous reptiles are being rapidly reduced in numbers, and unless special means be speedily taken for their preservation, they will ere long entirely cease to exist. During the historic period the islands where giant tortoises are known to have existed constitute three distinct groups. Two of these are situated in the Indian Ocean, and comprise Aldabra, to the north-west of Madagascar, and the Mascarene Group — including Reunion, Mauritius, and Rodriguez — lying to the east of the same ; while the third or Galapagos Group, taking its name from the Spanish word' for tortoise, is situated in the far distant South Pacific, off the western coast of South America. During the sixteenth and seventeenth centuries, the tortoises are stated to have existed in enormous numbers in all the above-named islands ; but as they afforded a most valuable supply of food, and could be kept alive on board ship, their numbers were rapidly reduced in those of the Indian Ocean, and Aldabra is now the only island in that area where they still exist in a wild state. Many of these tortoises were, however, exported to the Seychelles, and it is believed, as we shall notice below, that one carried 56 TORTOISES AND TURTLES. thence to the Mauritius is the only living example of the species that formerly inhabited Rodriguez. Regarding the abundance of these tortoises in the latter island, Francois Leguat, writing in 1691, observes that " there are such plenty of land-turtles in this isle, that sometimes you see a three thousand of them in a flock, so that you may go above a hundred paces on their backs." In Mauritius they were still abundant in 1740; but about 1761 they were probably scarcer, as thousands were then imported from Rodriguez as food for the patients in the hospitals of the Mauritius. The continued exportation, — some ships taking as many as four hundred at a time, — coupled with the destruction of their eggs and young, finally led to their extermination in both Mauritius and Rodriguez ; this extirpation having probably taken place early in the present century. The Reunion tortoise, of which very little is known, seems to have disappeared at a still earlier date ; while of the Galapagos species, we shall speak later. The total number of species of giant tortoises known to have existed within f&hPv ELEPHANT-TORTOISE. the historic period is about fourteen ; the whole of which are characterised by their large size, their long necks, and the uniformly dark brown or black colour of their shells. They may be divided into four groups, according to their geographical distribution, each characterised by certain structural peculiarities. The first group comprises the four Aldabra tortoises, characterised by the presence of a nuchal shield on the front of the carapace, and the distinctness of the gulars on the front of the plastron. On the other hand, in the four best known Mascarene species, constituting the second group, the nuchal shield is wanting, while the two gulars have coalesced into one ; the plastron being characterised by its extreme shortness. Lastly, the third, or Galapagos group, with six species, presents a condition inter- mediate between that existing in the two others, the nuchal shield of the carapace being absent, while the gulars of the plastron remain double. We proceed to notice some of the species of each group. The best known of the four species from Aldabra is the elephant- Aldabra Tortoise. . tortoise (T. elephantina), which differs from the other three in having LAND-TORTOISES. 57 the horny shields of the carapace concentrically striated, and the plastron of the adult notched behind. One of the species (T. gigantea) with smooth shields on a truncated plastron is peculiar in having the caudal shield divided, as in the Burmese brown tortoise. The elephant-tortoise appears to be one of the largest of all the species, attaining a length of about 4 feet. At the present day it is very scarce in its native island, where the few survivors receive a certain amount of protection from the Government of Mauritius, to which Aldabra belongs. There are, however, a few individuals living in Mauritius and the Seychelles. Mascarene Of the Mascarene species, the three species from Mauritius Tortoises. (^p indica, trisserrata, and inepta), all of which are extinct, are characterised by the thinness of their carapace, of which the margins are thickened. The Rodriguez tortoise (T. vosmoeri) has a still thinner carapace, which in the male does not shelve down in front in the usual manner. Allusion has already been made to the numbers in which these tortoises existed in Leguat's time ; but till quite recently it was thought that the species was totally extinct. It appears, however, that in the Artillery barracks of Port Louis in the Mauritius, there lives a very ancient tortoise which, in the opinion of Dr. Giinther, is probably of this species. This tortoise is one of two which were imported into the Mauritius by the navigator, Captain Marion du Fresne from the Seychelles in 1766 ; one of these having been subsequently presented to the London Zoological Gardens in 1832 by Sir C. Colville. The latter weighed 289 lbs., and its shell measured 4 feet 4| inches in length along the curve, and 4 feet 9 inches in width ; while in the Port Louis specimen the circumference of the shell is 9 feet 3 inches, and its height 2 J feet. Marion's tortoise, as the Port Louis example is called, is thus definitely known to have lived for a hundred and twenty-seven years, and as it was doubtless of large size when brought from the Seychelles, and since all these tortoises take an immense time to reach large dimensions, it is highly probable that it is an actual survivor from the enormous herds that existed in Rodriguez in Leguat's time. From a peculiarity in the structure of the hinder vertebrae of the neck, it appears that the tortoises of this species have the power of raising their necks to a nearly vertical position, which would give them a wide range of vision. This elevated range of vision would accord well with the account given by Leguat, who writes concerning these tortoises as follows. " There's one thing very odd among them ; they always place sentinels at some distance from their troop, at the four corners of the camp, to which the sentinels turn their backs, and look with the eyes, as if they were on the watch." Galapagos The various islands of the Galapagos Group, such as Abingdon, Tortoises. Albemarle, Chatham, Hood, and Charles, are the respective homes of one or more species of giant tortoise. Of the various specie's inhabiting these islands, the blackish tortoise (T. nigrita), which is the one given in the illustration on p. 54, agrees with two others (T. nigra and T. vicina) in having the horny shields of the carapace concentrically striated in the adult ; the figured species differing from T. nigra in having the plastron notched, instead of truncate behind. In the other three species the shields on the back are smooth, while the plastron always has its hinder end truncated. In the North Albemarle tortoise ( T. microphyes), the width of the bridge connecting the upper and lower 58 TORTOISES AND TURTLES. shells is of considerable length, and the shell itself stout. On the other hand, in the saddled tortoise (T. ephij^pium) and the Abingdon tortoise (T. abingdoni) the same bridge is relatively short, and the shell is remarkable for its thinness ; the carapace being much narrowed anteriorly, where it is so pinched in at the sides as to have a sharp ridge on the back. In the former of these two species the shell still retains the usual bony framework, but in the second it is soft and leathery. Both have very long necks, which are carried nearly vertically ; and in the Abingdon species the notches in the front end of the shell are so large that in a front view the animal appears merely to have a kind of mantle thrown over the body. It is hard to see what can be the object of this softening and atrophy of the shell ; but it is quite clear that it renders the animals very liable to injury, and thus probably accounts for the fact that none of them have been brought alive to Europe. The carapace of this species attains a length of 38| inches, and the weight of one individual was just over 200 lbs. The best account of the habits of the Galapagos tortoises is one given by Darwin, regarding the species figured in our engraving, which inhabits, apparently, most of the islands of the group. These tortoises frequent in preference the high damp parts, although they likewise live in the lower and arid districts. Very numerous in individuals, some grow to such a size that it requires six or eight men to lift them, while they will yield as much as 200 lbs. of meat. " The old males are the largest, the females rarely growing to so large a size ; the male can be readily distinguished from the female by the greater length of its tail. The tortoises which live on those islands where there is no water, or in the lower and arid parts of the others, feed chiefly on the succulent cactus. Those which frequent the higher and damp regions eat the leaves of various trees, a kind of berry, which is acid and austere, and likewise a pale green filamentous lichen, that hangs in tresses from the boughs of the trees. The tortoise is very fond of water, drinking large quantities, and wallowing in the mud. The larger islands alone possess springs, and these are always situated towards the central parts, and at a considerable height. The tortoises, therefore, which frequent the lower districts, when thirsty, are obliged to travel from a long distance. Hence, broad and well-beaten paths branch off in every direction from the wells down to the sea-coast; and the Spaniards by following them up, first discovered the watering-places. When I landed at Chatham Island, I could not imagine what animal travelled so methodi- cally along well-chosen tracks. Near the springs it was a curious spectacle to behold many of these huge creatures, one set eagerly travelling onwards with outstretched necks, and another set returning after having drunk their fill. When the tortoise arrives at the spring, quite regardless of any spectator, he buries his head in the water above his eyes, and greedily swallows great mouth- fuls, at the rate of about ten in a minute. The inhabitants say that each animal stays three or four days in the neighbourhood of the water, and then returns to the lower country ; but they differed respecting the frequency of these visits." After mentioning that some tortoises live on islands where the only water they obtain is that which falls as rain, and also that the inhabitants of the Galapagos Islands, when overcome with thirst, are in the habit of killing a tortoise and drinking the water contained in its interior, the writer proceeds as follows : — " The LAND-TORTOISES. 59 tortoises, when purposely moving towards any point, travel by night and day, and arrive at their journey's end much sooner than would be expected. The inhabitants, from observing marked individuals, consider that they travel a distance of about eight miles in two or three days. One large tortoise, which I watched, walked at the rate of sixty yards in ten minutes, that is three hundred and sixty yards in the hour, or four miles a day, — allowing a little time for it to eat on the road. During the breeding-season, when the male and female are together, the male utters a hoarse roar or bellowing, which, it is said, can be heard at a distance of more than a hundred yards. The female never uses her voice, and the male only at these times ; so that when the people hear this noise, they know that the two are together. They were at this time (October) laying their eggs. The female, where the soil is sandy, deposits them together, and covers them up with sand ; but where the ground is rocky, she drops them indiscriminately in any hole ; Mr. Bynoe found seven placed in a fissure. The egg is white and spherical ; one which I measured was 7| inches in circumference, and therefore larger than a hen's egg. The young tortoises, as soon as they are hatched, fall a prey in great numbers to the carrion-feeding buzzard (Polyborus). The old ones seem generally to die from accidents, as from falling down precipices ; at least, several of the inhabitants told me that they never found one dead without some evident cause. The inhabitants believe that these animals are absolutely deaf ; certainly they do not hear a person walking close behind them. I was always amused when over- taking one of these great monsters, as it was quietly pacing along, to see how suddenly, the instant I passed, it would draw in its head and legs, and uttering a deep hiss fall to the ground with a heavy sound, as if struck dead. I frequently got on their backs, and then giving a few raps on the hinder part of their shells, they would rise and walk away ; — but I found it difficult to keep my balance." Like their Mascarene allies, the Galapagos tortoises are much esteemed as food; and in order to see whether they were sufficiently fat to be killed, the inhabitants were accustomed to make a slit beneath the tail, through which the interior of the body could be seen. With the usual hardihood of reptiles, the rejected individuals appear to have recovered completely from this severe operation. From several of the islands the giant tortoises have already dis- appeared, and it is much to be feared that they will soon cease to exist throughout the Galapagos Group. Dr. G. Baur, who visited Albemarle in 1891, reports, however, that he made a large collection of these reptiles, one specimen weighing more than 400 lbs., and its carapace measuring 4 feet in a straight line. The familiar Grecian tortoise (T. grceca) brings us to the sixth main group of the genus, which comprises seven Old World species of small or medium size, characterised by the carapace being brown or olive, which may be either uniform, or spotted with black, or black and yellow ; by the gular shields on the plastron being distinct ; and by the slight prominence and shortness of the ridge on the palate. The Grecian tortoise belongs to a section of the group in which the anal or hindermost shields of the plastron meet in the middle line by a suture of considerable length ; and it is further characterised by the presence of five claws on the fore-foot. From its nearest allies it may be distinguished by the fifth vertebral shield of the carapace being much broader than the third; the 6o TORTOISES AND TURTLES. caudal shield being usually double, and there being no large tubercle on the inner side of the thigh. The shell of this species is moderately vaulted, and not much expanded behind, while its margins are not serrated. The nuchal shield is very long and narrow; in the male the divided caudals are much incurved; and the shields of the back show a strongly-marked concentric striation. In colour, the shell is bright yellow, with the shields of the carapace spotted and bordered with black, and a broad band of black running along each side of the plastron. The length of the shell is about 5£ inches. Mainly a South European species, the Grecian tortoise inhabits the Balearic Islands, Corsica, Sardinia, Sicily, Italy, Dalmatia, the Balkan Peninsula, and the Greek Archipelago, while it also occurs in Syria. The allied but larger Algerian tortoise (T. ibera), in which the shell attains a length of about 9 inches, may be distinguished by the fifth vertebral shield being not broader than the third, by the single caudal shield, and the presence of a large subconical tubercle on the inner surface of the thigh. In colour, this species differs from the last in having the plastron more or less spotted with black, while in some examples the carapace is uniformly brown. Its range includes North-Western Africa, Syria, Asia Minor, Trans- caucasia, and Persia. A third species often represented among the shiploads of these reptiles imported into England, is the margined tortoise {T. mar- ginata), which attains a length of 11 inches, and appears to be confined to Greece. The absence of an enlarged tubercle on the thigh serves to distinguish it from the preceding species ; from which it also differs by the longer and more depressed shell, in which the hinder margin is much expanded, and more or less serrated. Usually the carapace of the adult is black with a small yellow or greenish spot on each shield; while the ground-colour of the plastron is yellowish, each of its shields being marked by a black patch, which generally takes a triangular form. This species appears to be confined to Greece ; but in Lower Egypt and Syria is replaced by the smaller Leith's tortoise (T. leithi), in which the carapace is relatively shorter and more deeply notched in front, while the form and arrangement of the tubercles on the fore-limb is different. All these tortoises appear identical in their habits, frequenting dry and sandy places, and being extremely fond of sunshine, in which they will bask by the hour together. In certain parts of Greece and the south of Italy, the Grecian tortoise is found in great numbers ; and in the markets of Sicily and Italy it is regularly exposed for sale as an article of food. At the approach of winter it buries itself deep in the earth, where it remains during the cold months, usually reappearing in GRECIAN TORTOISE. LAND-TORTOISES. 61 April, but in Sicily as early as February. Although its main food consists of plants and fruits, it will likewise consume such snail's, worms, and insects as it may meet with during its wanderings. In captivity, where they have been known to live for a great number of years, these tortoises display great partiality for milky plants, such as lettuce; and they are always fond of a bath. At the approach of rain they always hide themselves, but in fine weather remain abroad throughout the day. In excavating a burrow for the winter's sleep, the earth is dug up by the strong fore-limbs, and thrown out from the hole by the hinder pair. The pairing-season commences immediately after the awakening from the winter sleep ; and in May or June the female lays from eight to fifteen hard-shelled white eggs, of about the size of a hazel-nut. These are deposited in a hole in the earth in some sunny spot, and after being carefully covered up, are left to hatch. By September the young tortoises are about the size of half a walnut-shell, and present an exceedingly comic appearance. There are certain other species belonging to the same group as Other Species. _, , r ° ° o tr the Grecian tortoise, which demand a brief notice. Among these is the handsome elongated tortoise (T. elongata), from Bengal, Burma, Cambodia, and Cochin China, taking its name from the great length of the depressed shell of the males ; the females being much smaller, with a relatively shorter and wider shell. These tortoises differ from the European species by the anal shields of the plastron having a very short line of union in the middle, even if they meet at all. The ground-colour of the shell is greenish yellow, upon which is an irregular black patch in each shield, which may occupy nearly the whole area of such shields, leaving merely a narrow yellow margin, or may be much broken up and indistinct. The male attains a length of between 10 and 11 inches. Forsten's tortoise (T. forsteni), from Celebes and Gilolo, may be distinguished by the want of a nuchal shield in the front of the carapace. Lastly, we have Horsfield's tortoise (T. horsfieldi), which, while allied to the European species, differs in having but four claws on the fore, as well as on the hind-feet. This tortoise inhabits the deserts, oases, and even mountains of Central Asia, where it ranges from the Aralo-Caspian region and the Kirghiz Steppes to Afghanistan. The shell, which is considerably depressed and not much longer than broad, has a brown or olive ground-colour above, which may be either uniform or blotched with black ; while beneath, it has large patches of black, which sometimes almost cover the whole surface. Writing of the elongated tortoise, Dr. J. Anderson says that it is active in its habits, and that the male is very confiding, eating readily from the hand, although the female, when touched, at once withdraws within the shell. Captive specimens were observed to be very restless at night ; they feed freely on plantains, but a female on occasion ate some dead prawns and fish, which had been procured to feed some soft-tortoises. Horsfield's tortoise, although equally fond of immersing its lower shell in water, is said to be more brisk in hot weather than are the European species ; it is purely diurnal in its habits, not venturing forth till after sunrise, and retiring to rest before sunset. Its food in the wild state is stated to be entirely of a vegetable nature ; snails and worms being never eaten. Anguiated The angulated tortoise (T. angulata), of South Africa, together Tortoise. with an allied species {T. yniphora) from an island near the Comoros, 62 TORTOISES AND TURTLES. constitute the last and seventh group of the genus, and are distinguished from all the others by the great prolongation of the anterior extremity of the plastron, which is covered by a single gular shield only. The former attains a length of about 7£ inches, and has an elongated and very convex carapace, of which the hinder margin is at most but slightly serrated. In colour, the shell is yellow above, each shield being bordered with black, and usually ornamented with a black spot in the centre ; while the plastron is black in the middle, or has some large black blotches. Areoiated Nearly related to the true tortoises, with which it agrees in the Tortoise. general structure of its shell, the areoiated tortoise (Homopus areo- latus), of South Africa, together with three other allied species from the same continent, differs by the absence of the median ridge on the front of the palate characterising all the former, and is on this account referred to a distinct genus. If the horny shields be stripped from the carapace, it will be found that the underlying neural bones, instead of being alter- nately octagonal and quadran- gular, are irregularly hexagonal, with the shorter of the two lateral surfaces placed posteri- orly ; since, however, the same feature occurs in some of the true tortoises, it is not absolutely characteristic of the genus. The areoiated tortoise is a small species, with a shell of only 4 inches in length. It is char- acterised by having only four claws on the front feet, and by its depressed carapace, which is of equal width throughout, and has even margins. On the back, the shields are more or less inflated, and separated from one another by deep channels ; the centre of each shield having a depressed areola, surrounded by concentric grooves. In colour, the carapace is olive, with a reddish brown centre to each shield ; while the plastron is brown in the middle, and yellow at the edges. A second species (H. femoralis) differs by having the hinder margin of the shell serrated, and a conical tubercle on the hinder surface of the thigh ; while in a third (H. signatus), there are five toes on each fore-foot. Lastly, H. nogueyi differs from all the others in its vaulted carapace, which is gibbose behind ; this species being from Senegal, while the other three are South African. In general habits it is probable that the members of this genus closely resemble the true tortoises. Three remarkable tortoises inhabiting tropical Africa constitute a genus distinguished at a glance from the other members of this section of the family by the circumstance that the hinder portion of the carapace is articulated to the anterior moiety by a ligamentous hinge, upon which it is freely movable, so that when the animal is withdrawn the hinder extremity of AKEOLATED TORTOISE. Hinged Tortoises. HINGED TORTOISES. 63 the shell can be completely closed. This hinge runs between the fourth and fifth costal bones and the seventh and eighth marginals of the shell. The skull agrees with that of the preceding genus, in the absence of a median ridge on the front of the palate, while the neural bones of the carapace are hexagonal and short-sided behind, and the caudal shield is undivided. The costal bones of the carapace differ, however, from those of the tortoises described above, in being of nearly equal width throughout, instead of alternately narrow at one end and broad at the other. Of the three species of the genus, the dentated hinged tortoise (Cinixys erosa), from Guinea and the Gabun, is characterised by the front and hind margins DENTATED HINGED TORTOISES (J nat. size). of the carapace being everted and strongly dentated ; by the absence of a nuchal shield, the projection of the extremity of the plastron in front of the carapace, and the sloping contour of the hinder extremity of the latter. The length of the shell is 9 inches ; its general colour above being dark brown, with lighter centres to the shields, and the lower sides of the costal shields yellowish ; while on the plastron the shields have dark brown centres and yellowish margins. In the nearly allied Home's hinged tortoise (C. homeana), from the same regions, there is a nuchal shield, the extremity of the plastron does not project in advance of carapace, and the hinder extremity of the latter descends vertically. On the other hand, Bell's hinged tortoise (C. belliana), which ranges right across tropical Africa, the margins of the carapace are neither everted nor serrated ; a nuchal shield being present on the front of the carapace. In length the latter does not exceed 1\ inches. 64 TORTOISES AND TURTLES. In habits the hinged tortoises show a complete transition from the land tortoises to the terrapins, and thus fully justifies the conclusion, arrived at from structural considerations, that both groups should be included in a single family. According to the observations of Monteiro, it appears that Bell's hinged tortoise is essentially a land reptile, inhabiting regions formed of gneiss rocks or other dry localities, where it is active during the hot rainy season, but in the cooler portion of the year, from May to October, according to native reports, lies deeply buried in the earth. Both the other species, on the contrary, seem to be mainly aquatic in their habits ; the dentated hinged tortoise, which is fairly common in Guinea, being stated to spend a large portion of its time in the water, where one specimen remained for up- wards of a month. According to Falkenstein, it is found in rivers, even close to the sea, from whence it emerges to lay its eggs on their banks. In spite of its club -like feet, it dives and swims with facility; captive examples descending to the bottom of a deep vessel in which they were kept. On land, its motions are, however, slow and deliberate in the extreme ; and have been com- pared to those of the minute- hand of a clock. Its food is of a vegetable nature ; one captive specimen displaying great partiality for cherries. By the inhabitants of Guinea these tortoises are eagerly sought after as food, and are thus difficult to obtain by Europeans. The last member of this section of the family is the spider- tortoise {Pyxis arachnoides) of Madagascar, which is the sole representative of a genus characterised by the presence of a transverse hinge across the front of the plastron, by which means the anterior lobe of the latter can be bent upwards so as to close the front of the shell. In having the neural bones of the carapace alternately octagonal and tetragonal, this species approaches the true tortoises nearer than do the hinged tortoises. In length the shell is only just over 4 inches ; its coloration is yellow, with radiating black bands from the centres of the shields of the back. The whole of the tortoises hitherto described are collectively characterised by the absence of all trace of webbing in the toes, by the presence of not more than two joints, or phalanges in each toe, by the meta- carpal bones of the fore-foot being but slightly, if at all, longer than wide, and also by the majority of the bony neural plates of the carapace being hexagonal, with their shorter lateral surfaces posteriorly placed, or alternately octagonal and tetragonal. On the other hand, in the remaining members of the family, the bell's hinged tortoise. Spider-Tortoise. Land-Terrapins. LAND-TERRAPINS. 65 digits are usually furnished with webs, or at least a rudiment thereof, while the middle toe of each foot has three joints, and the metacarpal bones are elongated. We have first to deal with a small group, mainly confined to the Oriental region, which both in structure and habits tends to connect this section of the family with the preceding one. These forms, as shown in the right-hand figure of the illustration on p. 42, agree with the hinged tortoises in that most of the hexa- gonal neural plates of the carapace have the shorter of the two lateral surfaces placed posteriorly and the longer anteriorly. Moreover, if the horny shields from the plastron be removed, it will be found that the entoplastral, or median unpaired bone of that part of the skeleton, is crossed by the groove marking the boundary between the humeral and pectoral shields. Spinose Land- The spinose land-terrapin (Geoemyda spinosa) may be taken as Terrapin. a well-known example of the first genus, characterised by the absence of a hinge in the plastron, and of a bony temporal arch on the sides of the skull. The three species of this genus are large-sized tortoises, confined to Burma and the Malayan region ; the spinose land-terrapin having a shell of 8 inches in length, while that of the great land-terrapin (G. grandis), from Burma and Siam, measures upwards of 16 inches. In the former of these two species both the front and hinder margins of the shell are deeply serrated ; whereas in the latter, as well as in the third representative of the genus, only the hinder border is thus ornamented. The colour of the carapace in these terrapins is brown or blackish, frequently with darker markings. Together with the other members of the group, they differ from the majority of the terrapins in having the head covered with a continuous skin, instead of with small shields. The small size of the webs of these terrapins indicates that in habits they are probably in part aquatic and in part terrestrial, cnaibassa The Chaibassa terrapin {Nicoria tricarinata) figured in the Terrapin, illustration on p. 66, and taking its name from a district in Bengal, is selected to represent a genus common to the Oriental region in the east, and Central and South America in the west, distinguished from the preceding by the presence of a bony temporal arch to the skull. Of the seven species of this genus, the smallest (here figured) has a shell of only 5 inches in length, but in a larger one it may measure as much as 16 inches. While in the figured Chaibassa terrapin both fore and hinder margins of the shell, as shown on the left-hand figure on p. 42, are entire, in other species either one or both of these may be deeply serrated. The Chaibassa species, which ranges from Bengal to Assam, has the carapace dark brown or black in colour, with the three longitudinal ridges from which it takes its name yellow; the plastron being uniformly yellow, and the neck and limbs blackish. From the larger three-keeled terrapin (N~. trijuga), of India and Burma, this species is further distinguished by its more convex shell, which descends very abruptly behind, as well as by the rudimentary condition of the webs between the toes ; on both of which grounds it may be regarded as more exclusively terrestrial in its habits. A fossil shell of the Chaibassa terrapin, represented in the right figure on p. 42, has been obtained from the Pliocene rocks of the Siwalik Hills of Northern India, thus indicating the extreme antiquity of the species. In some individuals the hinder half of the plastron is connected with the upper shell merely by ligament. vol. v. — 5 66 TORTOISES AND TURTLES. Hinged The third genus of this group (Cyclemys), which is confined to Terrapins. India, Malayana, and the south of China, is represented by some half a dozen species, which, while agreeing with the members of the foregoing genus in the presence of a bony temporal arch to the skull, differ by having a well-marked transverse ligamentous hinge across the middle of the plastron, whereby its hinder lobe is rendered movable, and capable of more or less com- pletely closing the posterior aperture of the shell. None of the species have a shell of more than 8 inches in length. The genus may be subdivided into two groups, each containing three species. In the former, as represented by G. dhor, of Northern India and the Malayan region, the plastron, which is notched behind, cannot completely close the shell; while the hinder margin of the carapace is serrated. In the second group, on the other hand, of which the Amboyna hinged terrapin (0. amboinensis) is a familiar example, the plastron is capable of completely closing the hinder aperture of the shell, while the posterior margin CHAIBASSA TERRAPIN (§ Iiat. size). of the carapace is not serrated. These species also have the shell keeled on the back in the young state. In the Amboyna species, as also in C. flavomarginata, the hinder end of the plastron is entire, although in a third (C. trifasciata) it is notched. Agreeing with the hinged terrapins in the presence of a trans- verse ligamentous hinge across the middle of the plastron, by the aid of which the openings of the shell can be closed, the two North American species of box-tortoises, together with all the remaining members of the family, differ from the former in that the hexagonal neural bony plates of the carapace have the shorter of their two lateral surfaces placed anteriorly, instead of posteriorly, this arrangement being shown when the shell is stripped. The presence of the hinge in the plastron serves to distinguish the box-tortoises from all the members of the second group, with the exception of the pond-tortoises, while from the latter they are separated by the beak being hooked, and the absence of a bony temporal arch to the skull. In the box-tortoises the head is covered with smooth skin above, the toes having only a rudimental web, and the tail is short. The Carolina box-tortoise (Cistudo Carolina) is a somewhat variable species as regards size, the length of the shell ranging from a little over 4 to somewhat more than 5 inches. The highly convex carapace is almost hemispherical in shape, and is BOX-TORTOISES. 67 .attached to the plastron solely by ligament, so that the whole shell can be com- pletely closed. As a general rule, the upper shell is dark brown or blackish, with yellow spots, or brownish yellow, with dark brown spots or rays, while there may be an interrupted yellow streak down the middle of the back. The plastron may be either a uniform dark brown or blackish, or may have irregular yellowish blotches on a ground or the same, while in some instances it is yellowish with dark blotches of variable size. The range of this species embraces the Southern and South-Eastern United States and Mexico. In the ornate box-tortoise, from Nebraska and some neighbouring states, the shell is more depressed, and the Carolina box-tortoise [\ nat. size). plastron and carapace are connected together by a very short bony bridge, so that the shell cannot be completely closed. The toes, moreover, have no distinct webs. The vaulted carapace of the box-tortoises, with their abruptly descending hinder profile, together with the rudimentary condition of the webs of the toes, at once proclaim the terrestrial habits of these reptiles, which form, indeed, one of the connecting links between the true tortoises and the fresh-water terrapins. Although mainly, if not entirely carnivorous (as is indicated by the absence of a median ridge in the front of the palate), the box-tortoises appear to resemble the true tortoises very closely in their general mode of life. According to some observers, they are more frequently to be met with in dry and even hilly districts, than in swamps. They are, however, partial to spots where colonies of night- 68 TORTOISES AND TURTLES. herons are in the habit of nesting, owing to the quantity of insects, snails, worms, and fragments of fish to be met with in such localities ; and they are frequently found in woods where the ground is either moist or swampy. At times they will, however, enter the water of their own free will ; and they have been seen half-buried under loose earth or moss in search of worms and insects. Unlike most members of the family, the box-tortoises shun the light, and are most active during the evening and night, shutting themselves closely up in their shells when the sun is shining brightly. The closure of the shell is also effected at the approach of any large animal ; and when thus securely boxed up, there are but few creatures these tortoises need fear. Like most other terrestrial tortoises, the females lay their eggs in holes dug in the ground by themselves ; the number laid being usually only five or six, whether the parents be half -grown or adult. Each individual egg is carefully covered with earth ; the time taken before the young are hatched being said to vary from eighty -eight to a hundred days. When first hatched, the young are well developed, and of great relative size and strength ; although their shells are still soft and cartilaginous, and the remnant of the yolk- sac depends from the plastron. In Pennsylvania both young and old bury theni- selves deep in the ground about the middle of October, where they remain till the latter part of April ; the spot selected having a dry soil, and being protected from the cutting blasts of the north. Many individuals which have not buried themselves sufficiently deeply, are, however, frozen to death during the winter slumber. On account of the strong and disagreeable flavour of their flesh, doubtless engendered by the nature of their food, the box-tortoises are not eaten. In marked contrast to the vaulted and abruptly -descending ' carapace of the box -tortoises, is the depressed and shelving shell of the pond-tortoises; this difference indicating a distinction in the habits of the two genera. Thus whereas the box-tortoises are, as we have seen, mainly land reptiles, the pond -tortoises are as decidedly aquatic in their mode of life. In addition to the difference in the form of the shell, the members of the present genus are readily distinguished from those of the last by the beak not being hooked, and by the presence of a bony temporal arch in the skull. In the shell the carapace is united to the plastron solely by ligament, while the plastron itself is more or less distinctly divided by a ligamentous transverse hinge, upon which its two lobes are movable. Agreeing with the box-tortoises in having the top of the head covered with undivided skin, the pond -tortoises differ by having the toes fully webbed, and also by the more elongated tail, which, while very long in the young, is of moderate length in the adult. Although the genus Emys was formerly made to include many of the fresh-water terrapins, it is now restricted to the European pond-tortoise (E. orbi- cularis), and a nearly allied North American species. The former, which is familiar to most visitors to Southern Europe, is characterised by the short oval form of its carapace, which is widest posteriorly, and in the young state has a more or less distinct median keel. In colour, the upper shell of the adult is dark brown or black, ornamented with a variable number of light, usually yellow, dots or radiating streaks ; the plastron being either yellow, brown and yellow, or almost wholly blackish brown. In the young, however, the upper shell is dark POND-TORTOISES. 69 brown, and the lower black ; all the shields of the latter, as well as the marginal ones of the former, having a large yellow spot. The skin of the head, neck, body, and limbs is marked with yellow and blackish, in varying porportions ; the head of the male having brownish dots on a darker ground, while in the female the dots are yellow. When fully grown, the shell attains a length of *l\ inches, but in most of the specimens imported into England it is not much more than half that size. At the present day the pond-tortoise is found, in suitable localities, in South and East Central Europe, and South-Western Asia as far as Persia, and in Algeria. W European pond-tortoise (* nat. size). During the Pleistocene period, when the climate of Northern Europe must at certain times have been much more genial, the pond- tortoise had a much more extensive distribution, its fossilised remains having been found in the superficial deposits of Belgium, Denmark, Germany, Lombardy, Norfolk, Sweden, and Switzerland. The American species, which inhabits the north-eastern United States and Canada, has the carapace rather more elongate, and the tail shorter; the former being black with pale yellow or brownish circular spots, and the plastron yellow with a large black patch on each shield. The European species inhabits both stagnant and running waters, and may be 7o TORTOISES AND TURTLES. found alike in slow or swift-flowing streams, or in open lakes. During the day- time it leaves the water to bask in the sun on sequestered spots of the banks, where it remains without moving by the hour together, but towards sunset it begins to move, and remains active throughout the night. At the commencement of winter it constructs an underground chamber, in which it remains buried in slumber till spring, usually reappearing, if the weather be favourable, about the middle of April ; at which time it reveals its whereabouts by a peculiar whistling cry characteristic of the breeding-season. An excellent swimmer and diver, the pond-tortoise disappears beneath the water at the slightest sound ; while when on land its motions are far more active than those of the true tortoises. Agreeing with other carnivorous terrapins in the absence of a median ridge on the fore-part of the palate, this tortoise feeds chiefly upon worms, water-insects, crustaceans, frogs, newts, tadpoles, and fish. In devouring fish, they reject the air-bladder, which floats on the surface of the water ; and from the number of such floating air-bladders some idea may be formed as to whether a pond is numerously tenanted by these tortoises. In captivity, where they will live for years, pond- tortoises, in addition to their natural food, will readily eat raw meat ; and in this state they frequently become so tame as to take food from the hands of their masters. The eggs, varying from nine to fifteen in number, are laid at night during May in hollows dug by the female in dry soil, at a considerable elevation above the bank, where they are carefully covered up and left to develop. These tortoises are eaten by the inhabitants of all the countries in which they occur. The remaining: members of this extensive family, which may be Terrapins. - ■ collectively known as terrapins, and can receive but brief mention, have the plastron without any transverse hinge, and firmly connected by bone with the carapace, so that the whole shell is solid and immovable. They comprise a large number of species, arranged under eleven genera, and all that can be attempted in a work of the present nature is to select for special notice one or more species of such genera. Although many of these terrapins are exceedingly unlike one another ex- ternally, yet they are all so closely connected that the genera can only be dis- tinguished by the characters of the skull and the bony plates of the shell, so that our description must of necessity be somewhat technical. Sculptured The sculptured terrapin (Clemmys insculpta), of eastern North Terrapin. America, is selected as a fairly well-known representative of a genus of eight species. This genus, it must be premised, forms one of a group of four agreeing with the two last noticed in the absence of a longitudinal ridge on the fore part of the palate, and in the carnivorous habits of its various members. From the three allied genera, Clem/my s may be distinguished by the aperture of the inner nostrils in the skull being situated between the eyes, by the unpaired entoplastral bone of the lower shell being traversed by the groove formed by the junction between the humeral and pectoral shields, and by the upper part of the head being covered with a continuous smooth skin. The figured species belongs to a group of five, characterised by the median union of the anal or hindmost shields of the plastron being longer than that between the femoral shields ; and while four species of this group are confined to North America, Beale's terrapin (C. bealei), inhabits China, thus showing a distribution analogous to'that of the alligators. On TERRAPINS. 7i the other hand, the Caspian terrapin (C. caspica), ranging from the Caspian Sea to the Persian Gulf, the Spanish terrapin (C. leprosa), of Spain and North- Western Africa, and the Japanese terrapin (C. japonica), resemble one another in having the median union of the anal shields shorter than that of the f emorals. The sculptured terrapin, which attains a length of about 7 inches, is specially characterised by the toes being webbed only at their bases, by the upper jaw having a notch in the middle, on the sides of which are a pair of tooth-like projections, and by the serration of the hinder border of the carapace. The shell is much depressed, with a raised keel down the middle of the back, and the shields of the carapace orna- mented with the radiating and concentric striae from which that species takes its name. sculptured terrapin (£ nat. size). While the ground-colour of the carapace is blackish, the radiating lines are yellow ; the plastron being yellow, with a large black blotch on each of its shields. The soft parts are dark brown or olive, the sides of the head being speckled with red. The figured species is exceedingly abundant on the Atlantic side of the United States, from Maine to Pennsylvania and New Jersey. Frequenting both marshes and rivers, it leaves the water for much longer periods than its European congeners, and is sometimes found for months at a time in perfectly dry places. In wandering from one stream to another, it makes regular tracks through the woods, and is hence frequently termed in America the wood-terrapin. In its feeding and general mode of life, this terrapin presents no features distinguishing it from other carnivorous kinds. 72 TORTOISES AND TURTLES. TMck-Necked Nearly allied to the preceding is the thick -necked terrapin Terrapin. (Bellia crassicollis), from Tenasserim, Siam, the Malay Peninsula, and Sumatra, which, with a second species from Borneo, constitutes a genus dis- tinguished by the greater development of the bony buttresses connecting the upper with the lower shell, and by the hinder part of the head being covered with small horny shields. The feet are fully webbed, and the anterior vertebral shields of the carapace are more or less distinctly balloon-shaped. The typical species measures rather more than 6| inches in length ; and is of a general dark brown or black colour, usually with some yellow markings on the plastron, and some large spots of the same colour on the head. Several representatives of this genus are met with in a fossil state in the Pliocene deposits of North- Western India. Hamilton's The handsomely coloured Hamilton's terrapin (Damonia hamil- Terrapin. toni), from India, conspicuous for its black and yellow, highly vaulted, and three-keeled carapace, is the best known representative of a third genus, distinguished from the foregoing by the hinder aperture of the nostrils opening behind the line of the eyes, and the great breadth of the palate. Like the two preceding genera, the entoplastral bone of the plastron is traversed by the groove formed by the union between the humeral and the pectoral shields ; and the hinder part of the head is covered with small shields. Hamilton's terrapin has the elevated carapace marked with three interrupted longitudinal keels, or rows of nodose prominences ; the colour of the shell being dark brown or blackish, upon which are spots and streaks of yellow, and the soft parts having likewise a similar coloration. While in young individuals the hinder border of the carapace is strongly serrated, in the adult it becomes nearly smooth. This species attains a length of nearly 9 inches at the present day, but fossil examples found in the Pliocene rocks of Northern India were still larger. These fossil specimens lived with numbers of mammals belonging entirely to extinct species. There are four other species of the genus, ranging over Malayana, Southern China, and Japan. Saltwater The last representative of the group with a smooth palate and Terrapin. carnivorous habits is the North American genus Malacoclemmys, distinguished from the last by the head being covered with continuous skin, and by the groove formed on the plastron by the junction between the humeral and pectoral shields being situated in advance of the entoplastral bone. While two of the species inhabit the valley of the Mississippi, the salt-water terrapin {M. terrapin) is a frequenter of the salt-marshes of the Atlantic Coast. The latter has an oval and much depressed carapace, which attains a length of nearly 7 inches, and is characterised by the great width of the first and second vertebral shields; its general colour being either olive, with* black concentric lines, or upper surface of carapace of Hamilton's terrapin. TERRAPINS. 73 uniform blackish. The plastron is yellowish or reddish, with variable black markings. It is this species that generally forms the celebrated New York dish known as terrapin; but it would seem that other species are also used, as the following account refers to terrapins taken high up the rivers. The best terrapins go by the name of "diamond-backs," and do not generally exceed some 7 inches in length, although they may rarely measure as much as 10 inches, but all terrapin of larger dimensions belong to the inferior kinds, ordinarily designated " sliders." According to Mr. W. M. Laffan, " terrapin are caught all the way from Savannah and Charleston to the Patapsio River at Baltimore, but the genuine diamond-back belongs only to the Upper Chesapeake and its tributaries. The majority of the sliders are brought to Baltimore from the James River. The terrapin-catchers make from five to twenty dollars per week, and they find the reptile, or * bird,' as the bon vivant calls it, by probing the mud in the shallows with sticks. The terrapin is dormant, and when found is easily secured. A 4 -lb. terrapin taken about September 15th will exist prosperously in a dark, cool place, without food or drink, until April 15th, and (the dealers say) will gain two ounces in weight. After that time it gets lively and active, and will take hold of a finger with great effusion and effective- ness. The male terrapin is known as a ' bull,' and the female as a ' cow.' The latter is much more highly prized, and generally contains about thirty eggs. No dish of terrapin is thought complete without being garnished with these." Formerly caught in shoals, the diamond-back has now become very scarce, and is, indeed, in some danger of extermination. The terrapin furnished in hotels is almost invariably " sliders," diamond-backs being sold to private houses only. Painted The seven remaining genera of the family constitute a distinct Terrapin. group, distinguished from the one including the six genera just men- tioned by the circumstance that the broad front portion of the palate of the skull is marked by one or two longi- tudinal ridges, and likewise by all the species being mainly or exclusively herbivorous in their diet. Among these, the large and exclusively American genus Chrysemys, with a dozen species, of which the painted terrapin (C. picta) is one of the best known, belongs to a subgroup of three genera, characterised by the bony buttresses con- necting the upper with the lower shell being short or of moderate size. From its allies Chrysemys is distinguished by the opening of the posterior nostrils being situated between the eyes, and by the entoplastral bone being situated in advance of the groove on the plastron formed by the junction of the PAINTED TERRAPIN. 74 TORTOISES AND TURTLES. Batagnrs. humeral with the pectoral shields. The painted terrapin of Eastern North America, which attains a length of 6 inches, and has a much depressed shell, takes its name from its brilliant coloration. Thus, the carapace is olive or blackish, with yellow lines bordering the shields, and its marginal shields red, with black concentric or crescentic markings ; while the plastron is yellow, sometimes with small streaks of black on the middle line, and the bridge red, with black markings. The soft parts have a brown or blackish ground-colour, with lighter bands, which are yellow on the head and red elsewhere. Eyed and Chinese The eyed terrapin (Morenia ocellata), from Burma, together with Terrapins. an allied species from Bengal, constitute a genus distinguished from the preceding by the aperture of the posterior nostrils opening behind the line of the eyes. The typical species, in which the shell measures nearly 9 inches in length, takes its name from the eye-like black spots ringed with yellow which adorn each shield of the back portion of the carapace. On the other hand, the Chinese terrapin (Ocadia sinensis), which is the sole existing representative of its genus, differs from Chrysemys in having the entoplastron intersected by the groove formed by the junction between the pectoral and humeral shields. The genus is of special interest as being represented by extinct species in the upper Eocene strata of the south of England and the Continent. The remaining members of the family, which are arranged under four genera, and may be collectively known as batagurs, are exclus- ively confined to India, Burma, and the Malayan region. They comprise the largest fresh- water representatives of the family, and are readily characterised by the great development of the vertical bony buttresses connecting the carapace with the plastron, which project as walls within the shell, so as partially to divide it into compartments. Of the four genera, Cachuga, which is represented by seven species from India and Burma, is readily recognised by the great elongation of the fourth vertebral horny shield of the carapace, which extends over four or five of the underlying neural bones. The smaller members, such as Smith's batagur (C. smithi), and the black - and - yellow batagur (G. tectum), of the Ganges and Indus, are characterised by the fourth vertebral shield terminating in front in a narrow point. Whereas the former of these has a depressed and feebly keeled shell, the latter, especially when young, has the carapace much vaulted, and the third vertebral shield produced behind into a conical elevation forming the highest part of the shell. The name of black-and-yellow batagur is derived from the irregular UPPER SURFACE OF CARAPACE OF SMITH'S batagur (I nat. size). BIG-HEADED TORTOISE. 75 black patches on the bright yellow plastron ; the carapace being brown. I have taken specimens of this pretty little batagur, which does not exceed 8 inches in length and is generally much smaller, near the fort at Calcutta. Like the under- mentioned dhongoka, it occurs fossil in the Pliocene deposits of Northern India. The larger species of the genus, such as the Indian dhongoka (C. dhongoka), which grows to over 14 inches, has the fourth vertebral shield broad in front, instead of being narrowed to a point. The three remaining genera, Callagur, Batagur, and Hardella, differ from the preceding in that the fourth vertebral shield of the carapace is not longer than the third ; but it will be unnecessary to point out the features by which they are severally distinguished. The largest of all is the true batagur {Batagur basca), in which the carapace measures upwards of 20 inches in length. All the batagurs are exclusively vegetable feeders, and the larger species are thoroughly aquatic in their habits, spending by far the greater portion of their time in the water. They abound in the larger rivers of India and Burma, where their huge shells form conspicuous objects as they rise to the surface to breathe. Describing the habits of a captive specimen, Dr. John Anderson states that when it rose to breathe "its nostrils were simply protruded above the surface of the water, and retained in that position for about half a minute, during which it made a long expiration, followed by a deep inspiration, the creature then slowly subsiding, tail-backwards, to the bottom. The animals, unless they were much irritated, never attempted to bite, but, when so treated, they sluggishly seized any object put in their way, holding it between their jaws with considerable tenacity, at the same time withdrawing the head into the shell. They moved about on the ground with considerable agility, supporting their heavy bodies erect on their legs, like a land-tortoise." Another species will occasionally snap, when, owing to the friction of its serrated jaws against each other, a peculiar kind of barking sound is produced. Batagurs are eaten in Lower Bengal by some of the inferior castes of Hindus, and are kept for this purpose in tanks. The Big-Headed Tortoise. Family PLATYSTERNID^E. This extraordinary creature (Platy sternum megacephalum), which is an inhabitant of the south of China, Siam, and Burma, is the sole repre- sentative, not only of a very remark- able genus, but likewise of a distinct family, which appears to be to a great extent intermediate between that of the tortoises and that of the snappers. The most peculiar feature about this tortoise is the disproportionately large size of its head, in which the SIDE VIEW OF SKULL OF BIG-HEADED TORTOISE. (From Boulenger). 76 TORTOISES AND TURTLES. beak is much hooked; and an examination of the skeleton will show that the temporal fossae of the skull differ from those of all the members of the preceding family in being roofed over with bone, as in the following family of the snappers. Moreover, the tail resembles that of the latter in its great length, and also in the circumstance that the articular surfaces of most of its vertebrae have the cup behind and the ball in front, whereas in the tortoise family just the reverse of this arrangement occurs. On the other hand, the carapace resembles that of the latter, and differs from that of the snappers in the absence of a rib-like process from its posterior angles passing backwards beneath the marginal bones. The THE BIG-HEADED TORTOISE {\ nat. size). carapace is characterised by its extreme depression and oval form; while the plastron is of moderate size, and connected with the carapace solely by ligament, so that bony buttresses are totally lacking. The head is covered with a continuous horny shield, and the hooked jaws are of great power. The toes are of moderate length, and but slightly webbed ; all, save the fifth in the hind-foot, being furnished with claws. The long and cylindrical tail becomes compressed at the end, and is covered with rings of quadrangular shields. In size this tortoise is small, the length of the carapace being only about 6 inches, and that of the tail some three- quarters of an inch more. In the adult the colour is olive-brown above, and yellowish brown beneath, but the young is more brilliantly coloured. Of the habits and mode of life of this tortoise, nothing appears hitherto to have been ascertained. MUD-TERRAPINS. 77 The Mud-Terrapins and their Allies. Families ClNOSTERNID^E and DermatemydidjE. The mud-terrapins (Cinosternum) bring us to the first of two nearly related families confined to the New World, all of which differ from those previously- noticed by the circumstance that the nuchal bone of the carapace gives off' from each of its hinder angles a long rib-process which underlies the marginal bones. From the second family, the mud-terrapins, of which there are eleven species inhabiting America north of the Equator, are broadly distinguished (as indeed they •V^*/V PENNSYLVANIAN MUD- TERRAPIN (J nat. size). are from all other members of the order) by the fact that there are but eight bones in the plastron, owing to the absence of the unpaired entoplastral bone. As regards their other characters, the mud-tortoises resemble the Testudinidce in the conformation of the vertebrae of the tail, and in the absence of a roof to the temporal fossa of the skull, as well as in the extreme shortness of the tail. The carapace is more or less depressed, and is articulated by a bony suture with the plastron; the latter having the gular shields fused into one, or wanting, and its fore and hind- lobes more or less movable. The toes are fully webbed, and with the exception of the fifth in the hind-foot, strongly clawed. The best known representative of the genus is the Pennsylvanian mud-terrapin (G. pennsylvanicum), which attains a length of about 4J inches, and inhabits eastern North America from New York to the Gulf of Mexico. In colour, the shell is brown or brownish above, and either yellow or brown beneath, the lines of junction between all the shields being dark 78 TORTOISES AND TURTLES. brown or blackish, while the head and neck are brown with yellowish spots. From other species of the genus it is distinguished by the large size of the plastron, in which the anterior lobe is narrower than the mouth of the shell. In general habits the mud-terrapins seem to be very similar to the fresh- water members of the tortoise family, although they prefer swamps and marshes to running waters. Carnivorous in their diet, they subsist chiefly on small fishes, insects, and worms, while they have been observed to capture newts. They will readily take a baited hook, and when thus caught sink rapidly and heavily to the bottom, thus causing the angler to believe that he has hooked a weighty fish. At the commencement of winter they bury themselves in moss, where they remain dormant till the following May. An extinct genus nearly allied to the mud- tortoises occurs in the Tertiary rocks of Baden. Maw's terrapin (Dermatemys mawi) may be taken as a good Maw's Terrapin. . . 'J & representative of the second family, all the three genera of which are restricted to Central America. This family connects the preceding one with the snappers, agreeing with the latter in the presence of an entoplastral bone, and with the former in the characters of the vertebrae of the short tail, which have the cup in front, and the absence of a roof to the temporal fossa of the skull. Maw's terrapin and its allies further agree with the mud-terrapins in the incompleteness of the series of neural bones of the carapace ; the hinder ones being wanting, and thus allowing the costal plates to meet in the middle line. Externally, the members of the present family may be distinguished from the Testudinidce by the presence of an additional series of infra-marginal shields between the marginals and those of the plastron — a feature which they possess in common with the big-headed tortoise and the snappers. Maw's terrapin, which attains a length of some 15 inches, and is the sole representative of its genus, has the plastron large, and connected with the carapace by an elongated bridge ; the gular shield being single, and the usual five other pairs of shields being present on the plastron. Unlike most other tortoises, there are twelve pairs of marginal shields, in place of the usual eleven. In the other two genera of the family — Staurotypus and Claudius — the plastron is reduced to a cross-like shape, and has but a short connection with the carapace ; while the number of paired shields on the former is only four or or three, and the chin is provided with a pair of wattle-like appendages, of which there is no trace in Maw's terrapin. While in the two species of Staurotypus the plastron is connected with the carapace by a bony bridge, in the single represen- tative of Claudius the junction is entirely ligamentous. This family is represented by several extinct genera in the Tertiary and Cretaceous strata of North America, one of which (Baptemys) had the full series of neural bones; and there appear to have been allied forms in the European Tertiaries. The Snappers and Alligator-Terrapins. Family CHELYDRID^:. Resembling the big-headed tortoise in the great relative size of their hook- beaked heads, and their elongated scaly tails, the snappers and alligator-terrapins SNAPPERS. 79 of North and Central America constitute a well-marked family by themselves. In the first place, they differ from the species named in that the majority of the vertebrae of the tail have the articular cup behind, and the ball in front ; while the temporal region of the skull is but partially covered with a bony roof. The American forms are further characterised by the relatively small size of the carapace, of which the hinder border is strongly serrated ; while the cruciform plastron is likewise small, and but loosely articulated with the upper shell by a very narrow bridge. Moreover, both the upper and lower shells are not completely ossified till very late in life, vacuities remaining for a long time between ALLIGATOR-TERRAPIN (TV nat. size). the costal and marginal bones in the former, and in the middle line of the latter. Then, again, the plastron is peculiar in that the abdominal shields, which are separated from the marginals by an inframarginal series, do not meet one another in the middle line, although they may be connected by some small, irregular, unpaired, additional shields. Further, the enormous head cannot be completely retracted within the carapace, of which the anterior margin is deeply excavated in order to afford it room ; and the chin is provided with one or more pairs of pendent wattles. With the exception of the fifth in the hind-limb, the toes are furnished with claws ; and the long tail is crested above. Alligator- The alligator-terrapin, or snapping turtle (Chelydra serpentina) Terrapin. js a giant among river-tortoises, and takes its name from a fancied 8o TORTOISES AND TURTLES. resemblance to an alligator surmounted by a chelonian shell. It is one of two species belonging to a genus characterised by the eyes being directed upwards and outwards, so that their sockets are visible in a top view of the skull ; by the tail being furnished with large horny shields on its lower surface ; as well as by the absence of the supramarginal shields found on the carapace of Temminck's snapper. The carapace, which may attain a length of at least 20 inches, is characterised by its rugose surface, bearing three well-marked tuberculated keels, which tend to become smoother with advancing age ; while its vertebral shields are remarkable for their great width. The snout is short and pointed, with a very narrow space between the eyes ; the skin is warty, and on the chin is developed into a pair of wattles or barbels. In the young the tail is as long or even longer than the shell, becoming relatively shorter in the adult ; its upper surface having a crest of large compressed tubercles, while the shields on the lower surface have been already alluded to. As in the other members of the family, the colour is a uniform olive-brown. The alligator-terrapin inhabits the rivers of North America to the eastward of the Rocky Mountains, from Canada to Mexico, and is also found in Ecuador. A second living species (C. rossignonii), distinguished, among other features, by the presence of four wattles on the chin, is met with in Guatemala and Mexico. Nearly allied to this is a third and extinct species (C. murchi- soni), from the Miocene rocks of Baden ; and as we have already seen that the mud-terrapins, and probably also Maw's terrapin, were represented in the Tertiary strata of Europe, it is not improbable that the Eastern Hemisphere may have been the original home of the present group of families. Temminck's Attaining considerably larger dimensions than the alligator- snapper, terrapin, Temminck's snapper (Macroclemmys temmincki) is dis- tinguished as a genus by the lateral position of the eyes, the sockets of which are invisible in a front view of the skull, as well as by the presence of three or four additional or supramarginal shields on the sides of the carapace, and by the under surface of the tail being covered with small scales. The triangular head is pro- portionately even larger than in the alligator-terrapin, and the carapace has three very strongly marked longitudinal ridges. In length, the shell may measure at least a couple of feet, the tail being somewhat shorter. This species inhabits North America from Western Texas to Florida, extending northwards to Missouri. Since the alligator-terrapin and Temminck's snapper appear to be very similar in their mode of life, their habits may be treated of collectively. Both these tortoises frequent alike the rivers and larger swamps of the United States, occurring in certain localities in enormous numbers, and most commonly in waters that have a muddy bottom, not even disdaining the most malodorous pools. As a rule, they lie in deep water, near the middle of the river or swamp, although at times they show themselves on the surface, where, with outstretched neck, they will float with the current. In populated districts the least sound is, however, sufficient to send them at once to the bottom, although in more remote regions they are less shy. At times they may be observed at considerable distances from the water, probably in search of food or of suitable spots to deposit their eggs. Temminck's snapper well deserves its name, since, from the moment of its escape from the egg, it commences to snap and bite at TURTLES. 8r everything within its reach; and an adult has been known to make a clean perforation with its powerful beak through the blade of an oar half an inch in thickness. When one of these tortoises is taken into a boat, Weinland states that it will rear itself up on its hind-legs, and with lightning-like speed throw itself half a yard forwards to bite an oar ; and they have been known to inflict terrible wounds on persons who have incautiously entered waters where they abound. In the water the movements of these reptiles are more rapid than those of most of their kin, and when in pursuit of prey they swim with surprising speed. Their food consists largely of fish, frogs, and other water-animals ; while they will also frequently seize and drag down large aquatic birds, more especially ducks and geese. Tame specimens, that were kept in a pond in the United States, proved terrible foes to the stock of fish contained in the same. The eggs, which vary from twenty to thirty in number, and are about the size of those of a pigeon, are deposited on the ground near the water, and are carefully covered over with leaves. In captivity these tortoises thrive well in Europe, if the water be kept at a sufficiently high temperature ; and a specimen of Temminck's snapper, which has lived for more than thirteen years in the Brighton Aquarium, grew to a length of between 4 and 5 feet from beak to tail, whereas, on its arrival, it measured less than a foot. In the confined limits of a tank the movements of this reptile were deliberate and sluggish, and gave no idea of the activity characterising the wild state. Although the flesh of the adult of this species has such a strong musky flavour as to be uneatable, that of the young is stated to be tender and palatable. The eggs are also sought after as articles of food ; and when two or three females have laid together, as many as from sixty to seventy may be taken from a single nest. The Turtles. Family Chelonidje. The families mentioned up to now have their feet more or less fully adapted for walking on land, and the majority of the toes furnished with well- developed claws or nails ; while the carapace is generally of a somewhat oval form. The true turtles, on the other hand, while agreeing with the foregoing in having their shells covered with horny plates, are at once distinguished by the limbs being converted into flattened paddles, in which, at the most, only two of the toes are furnished with claws. They are further characterised by the heart-like form of the carapace, within which the head can be only partially withdrawn ; while the plastron is never united by bone to the carapace, and vacuities remain in the latter between the costal and marginal bones either throughout life, or for a very long period. The skull has its temporal fossae completely roofed over by bone ; and the vertebrae of the very short tail have the articular cup in front and the ball behind. Entirely marine in their habits, and resorting to the shore only for the purpose of breeding, turtles differ from tortoises and terrapins in that the shells of their eggs are soft. In their entire conformation they are admirably adapted for an aquatic life, the body being depressed to facilitate rapid progress through the water, both the skull and shell being of unusually light and porous vol. v. — 6 82 TORTOISES AND TURTLES. Green Turtle. structure; while the limbs form most perfect paddles, capable of propelling the animals with great speed. The head is placed upon the neck in such a manner as to allow of the nostrils being readily raised above the surface of the water for the purpose of breathing, and the nostrils themselves can be hermetically closed by means of a fleshy valve. The three best known species of turtles, which are assigned to two genera, are inhabitants of all tropical and subtropical seas ; one species — the loggerhead — occurring in the Mediterranean, and occasionally wander- ing northwards. Widely celebrated as being the source of the far-famed turtle- soup of civic banquets, the green turtle (Chelone mydas) is one of two species belonging to a genus characterised by the presence of four pairs of costal shields on the carapace, and by the persistence of the vacuities between the costal and marginal bones of the latter throughout life. The plastron is, moreover, distinguished by the presence of an intergular shield between the two gulars ; while, as in the second genus, there is a row of inframarginal shields between the marginals and the proper shields of the plastron. The skull is of moder- ate size in comparison to the shell, with the sockets of the eyes placed nearly vertically, and separated by a 'broad bar of bone. Such are the characters common to the two species of the typical genus of the family. The green turtle is specially distinguished by its short beak, which is devoid of a hook at the tip, and by the shields of the carapace being in contact by their edges all through life. In the young, the carapace shows a faint median keel ; while its hinder margin is at most but feebly serrated at all ages. Generally there is but a single claw on each paddle, although, in some instances, young specimens also have a claw on the second digit. In colour, the shell of the adult is olive or brown, with yellowish spots or marblings ; while in the young it is uniform dark brown or olive above, and yellow beneath, the limbs being bordered with yellow on the upper surface, and inferiorly yellow with a brown spot near the extremity. The food of the species consists of seaweeds, especially the seawrack, upon which the turtles graze at the bottom of the water, rising occasionally to the surface to breathe. Generally rejected as food, the hawksbill turtle (C. imbricata) Ha/wksbill Turtle • enjoys thereby no respite from persecution, since it is eagerly hunted GREEN TURTLE. TURTLES. 83 for the beautifully mottled horny shields of its shell, which are the sole source of the tortoise-shell of commerce. In its young state, the hawksbill may be readily distinguished from the preceding species by the circumstance that the horny shields on the back of the three-ridged shell overlap one another like the tiles on a roof. With advancing age the shields gradually, however, become smooth, and in very old specimens they meet at their edges, as in other members of the order. At all ages the hinder margin of the carapace is more or less strongly serrated ; and the compressed and sharply hooked beak will always serve to distinguish at a glance a hawksbill from a green turtle. Moreover, the limbs always have two HAWKSBILL TURTLES SWIMMING (-fo nat. size). claws. In the adult, the shields of the carapace are beautifully marbled and mottled with yellow and dark reddish brown, while the plastron is yellow, and the shields on the head and paddles are brown with yellow margins. In size this species is somewhat inferior to the green turtle, the carapace attaining a length of about 32 inches, against 42 inches in the latter. In habits the hawksbill differs markedly from the green turtle, being exclusively carnivorous. Loggerhead The third, and probably the largest species of turtle, is the Turtle. loggerhead (Thalassochelys caretta), easily recognised by its enormous head and the presence of at least five costal shields on each side of the carapace, which differs from that of the two preceding species by becoming completely ossified in the adult state. The beak is strongly hooked ; and while in the young 84 TORTOISES AND TURTLES. Habits. there are usually two claws to each paddle, oue of these frequently disappears in the adult. In colour, the adult is brown above, and yellowish beneath ; but the young is uniformly dark brown or blackish. The Mexican loggerhead (T. kempi), from the Gulf of Mexico, differs in having a median ridge on the bone of each jaw, whereas in the ordinary species such ridges are confined to the investing horny sheath. According to Mr. Gosse, loggerheads feed on cuttles and other molluscs, their powerful beaks enabling them to crush strong conch-shells as easily as a man can crack a nut. Apart from the difference in their food, all turtles appear to be similar in their general mode of life, never leaving the sea except for the purpose of laying their eggs, and then shuffling along in an awkward, ungainly manner. During the laying season they resort to low sandy coasts, especially unfrequented tropical islands, in vast numbers ; and if once turned on their backs, while on shore, are unable to right themselves again. This habit of resorting to the land to lay their eggs clearly proves, it may be observed, the descent of turtles from fresh -water members of the order. Writing of the green turtles at Aldabra, one of the Seychelles group of islands, Mr. Spurs remarks that the males permanently frequent the bay of that island, the females when they attain full maturity (twenty or twenty- five years) disappearing alto- gether. When the latter come to the shore for the purpose of laying, their shells are covered with barnacles of two or three weeks' growth. Commercially, the females are more valuable than the males, and, as they are more easily captured, the proportion found on the island is one female to every ten males, although, for one of the latter, about ten of the former sex are hatched. Turtles generally come ashore on fine moonlight nights, displaying great caution in landing, and then generally uttering a loud hissing noise which serves to disperse many of their enemies. Once landed, the female turtle, writes Audubon, " proceeds to form a hole in the sand, which she effects by removing it from under her body with her hind-flippers, scooping it out with so much dexterity that the sides seldom, if ever, fall in. The sand is raised alternately with each flipper, as with a large ladle, until it has accumulated behind her, when, supporting herself with her head and forepart on the ground fronting her body, she, with a spring from each flipper, sends the sand around, scattering it to the distance of several feet. In this manner the hole is dug to the depth of eighteen inches, or sometimes more than two feet. This labour I have seen performed in the short space of nine minutes. The eggs are then YOUNG LOGGERHEAD TURTLE. TURTLES. 85 dropped one by one, and disposed in regular layers, to the number of one hundred and fifty, or sometimes nearly two hundred. The whole time spent in this part of the operation may be about twenty minutes. She now scrapes the loose sand back over the eggs, and so levels and smooths the surface that few persons on seeing the spot could imagine that anything had been done to it. This accomplished to her mind, she retreats to the water with all possible despatch, leaving the hatching of the eggs to the heat of the sand." During a season each female will lay three clutches of eggs, at intervals of from a fortnight to three weeks, usually from one hundred and twenty-five to one hundred and fifty in number. No sooner are the young turtles hatched, than hosts fall victims to land-crabs, frigate-, and other sea- birds, while, when they reach the sea, they are attacked by swarms of predaceous fishes. To escape the latter, the young reptiles allow themselves to be carried out by currents into deep water, where they are less readily seized. During the breeding-season the males fight desperately with one another, to the great joy of the sharks, by whom the disabled ones are seized. When first laid, the round eggs of turtles are never quite full, but before hatching become fully distended. In describing the breeding-habits of the turtles kept in a pond near the dockyard in Ascension Island, Moseley states that in the breeding-season the females dig great holes as large as themselves in a bank of sand, in which to deposit their eggs. The sand in which the eggs are laid does not feel warm to the hand, but during the daytime is rather cool, while it is at all times moist. Its temperature appears to undergo no material variation, owing to the depth at which the eggs are deposited ; such medium amount of heat being sufficient for the hatching. Although a large number of green turtle are captured by being turned on their backs while on shore, in the Seychelles and Bahamas they are harpooned. In Keeling Island the method of capture is described by Darwin as follows : — " The water is so clear and shallow that, although at first a turtle dives quickly out of sight, yet, in a canoe or boat under sail, the pursuers, after no long chase, come up to it. A man, standing nearly in the bows at this moment, dashes through the water upon the turtle's back, then, clinging with both hands to the shell of the neck, he is carried away, till the animal becomes exhausted, and is secured." In China and Mozambique turtles are captured by means of sucking- fishes, which are taken to a spot where the reptiles are basking upon the surface of the water. Each fish has a ring round its body to which a line is attached, and as soon as it securely fastens itself by its sucking-disc to the back of a turtle, both captor and captured are drawn ashore. Although those of the loggerhead have a somewhat musky taste, the eggs of the other species of turtle are much esteemed as articles of food, while all yield a valuable oil. Tortoise Shell "^"S a^rea(^y sa^' tortoise-shell is a product of the hawksbill turtle, and it is too often taken from the back of the living animal by the aid of heat, after which painful operation the unfortunate turtle is returned to its native element. As the raw tortoise-shell is very unlike the finished article, with which all are familiar, Bell's brief account of the process of manufacture may be quoted. The horny shields, as removed from the turtle, being highly curved, " the uneven curvature is first of all to be removed, and the plate rendered perfectly flat. 86 TORTOISES AND TURTLES. This is effected by immersing it in hot water, and then allowing it to cool under heavy pressure between smooth blocks of wood, or metallic plates. The surface is then rendered smooth, and the thickness equal, by scraping and tiling away the rough and prominent parts. In this way each plate receives an equal and smooth surface. But it is in many cases desirable to employ larger pieces than can be obtained from single plates, and two pieces are then united together in the following manner. The edges are bevelled off to the space of two or three lines, and the margins, when placed together, overlap each other to that extent. They are then pressed together by a metallic press, and the whole is submitted to the action of boiling water; and by this means the two pieces are so admirably soldered together as to leave no indication of the line of union. By the application of heat, also, the tortoise-shell may be made to receive any impression by being pressed between metallic moulds." Necklaces, etc., are made by pressing the fragments and dust in moulds. Turtles, more or less closely allied to the existing kinds, abound ' in marine strata of the Tertiary and Cretaceous epochs, some belong- ing to extinct and others to the living genera. Among the latter, the gigantic Hoffmann's turtle (Chelone hoffmanni), from the chalk of Holland, appears to have been allied to the hawksbill, but had a shell of some 5 feet in length. Extinct loggerheads occur in the London Clay ; and an allied extinct genus (Lytoloma), common to the same formation and the upper Cretaceous deposits, was remarkable for the great length of the bony union between the two branches of the lower jaw, and also for the circumstance that the aperture of the internal nostrils was placed right at the hinder extremity of the palate, as in crocodiles. In strata older than the Chalk, such as the Purbeck and other Oolitic rocks, we meet with turtles having heart-shaped shells, but clawed limbs, and a vacuity in the centre of the plastron, these forming an extinct family (Acichelyidce), from which the modern turtles have probably originated. Leathery Turtles. Family Dermochel yid^e. The remarkable leathery turtle, or luth (Dermochelys coriacea), which is the solitary survivor of a series of extinct forms, is one of those animals whose serial position is a matter of dispute among naturalists ; some of whom regard it as so different from all other Chelonians, that it ought to represent a suborder by itself, while others believe it to be merely a highly specialised form allied to the true turtles. From the evidence afforded by extinct species, the latter view, to our thinking, appears the more likely to be the true one. The essential peculiarity of the leathery turtle is to be found in the nature of its carapace, which is a mosaic- like structure composed of a number of irregular discs of bone closely joined together, and entirely free from the backbone and ribs. In certain extinct forms the carapace, on the other hand, is represented merely by a row of marginal bones ; from which it is inferred that these reptiles have been derived from true turtles by a gradual disintegration and breaking up of the carapace. In the living genus the TURTLES. 87 carapace is completely bony, and marked by seven prominent longitudinal keels ; but the plastron is much less fully ossified, and carries live similar keels, the unpaired entoplastral bone being wanting. The head, which is covered with small shields, is remarkable for its relatively large size and globose form ; the beak having two triangular cusps situated between three deep notches. The jaws differ from those of the true turtles in being sharp-edged from end to end, without any expanded bony palate ; and there is also an important difference in the structure of the skull itself, which may, however, be apparently the result of specialisation. As in the true turtles, the limbs are converted into flattened paddles, which are, LEATHERY TURTLE (3^ liat. size). however, completely destitute of claws; the front pair being much elongated, narrow, and pointed, while the hinder ones are short and truncated. The humerus, or bone of the upper arm, has the same general form as in the true turtles ; and is thus very unlike the corresponding bone of other members of the order. The process marked h in the figure on p. 88 is more developed than in the turtles ; and the foramen e at the lower end is unique in the order. Largest of living turtles, the leathery turtle exceeds 6 feet in length ; and while in the young the front flippers are equal in length to the shell, in the adult they become shorter. The general colour is dark brown, which may be either uniform, or relieved with yellow spots; the longitudinal tuberculated keels on the shell, as well as the margins of the limbs, being invariably yellow in the young. 88 TORTOISES AND TURTLES. This turtle is generally distributed throughout the tropical portions of the Atlantic, Indian, and Pacific Oceans, from whence it occasionally wanders to the coasts of cooler regions. Yearly becoming scarcer, it is, however, one of those species which stand a fair chance of extermination at no very distant date. Although but little is known as to the mode of life of this turtle, it appears that its food is chiefly of an animal nature, comprising fish, crustaceans, and molluscs. In the breeding- season it appears in numbers on the Tortugas Islands, off the coast of Florida, and sometimes in still greater abundance on the sandy shores of Brazil. Arriving somewhat later than the true turtles, it deposits its eggs in a similar manner, laying as many as three hundred and fifty, in two batches ; while at times, when three or more females have a nest in common, upwards of a thousand eggs may be found in a single spot. When hatched, the young turtles immedi- ately seek the water, where, however, they have almost as many foes as on land ; so that it is probable only a very small percentage arrive at maturity. The strength and weight of a full-grown individual are very great ; one captured some years ago, on the coast of Tenasserim, requiring the combined efforts of ten or twelve men to drag it on to the beach. The flesh has an unpleasant flavour, and is not, therefore, generally eaten. Gigantic as is the existing leathery turtle, it was considerably exceeded by some of its extinct allies. Among these, the huge Eosphargis, from the London Clay, with a skull of nearly a foot in length, apparently had a carapace consisting only of one median row of broad-keeled bony plates, and a border of marginal bones; while in Psephophorus, from the higher Eocene and Miocene strata of the Continent, both upper and lower shells were formed of mosaic-like bones, which, it is thought, were overlain- by horny shields. In the earlier Protostega and Protosphargis, from the Cretaceous rocks of North America and Europe, the upper shell appears to have been represented merely by a row of marginal bones, while the lower one was very stoutly ossified ; some of these early forms probably attained a length of from 10 to 12 feet. FRONT VIEW OF LEFT HUMERUS OF AN EXTINCT LEATHERY TURTLE. The Side-Necked Tortoises. Families CHELYID^E and PELOMEDUSIDJE. In place of withdrawing the head into the shell by means of an S-like flexure of the neck in a vertical plane, as in all the groups hitherto described, the remainder of the living tortoises with complete shells bend the neck side- ways in a horizontal plane (as shown in the illustration on p. 92), and thus bring the head within the margins of the shell. Accordingly, the group is collectively spoken of as the side-necked tortoises, or Pleurodira. This character is alone amply sufficient to separate the group from the foregoing assemblage SIDE-NECKED TORTOISES. 89 of S-necked or Cryptodiran tortoises, but since there are also certain features by which the skulls and shells of the two groups can be identified, it is im- portant that these should be noticed. As regards the skull, this is distinguished in the first place by the tympanic ring surrounding the aperture of the ear being complete, as may be seen by comparing the accompanying figure with the one on p. 47, and also by the circumstance that the lower jaw articulates by means of a LOWER AND SIDE VIEWS OF SKULL AND UPPER AND LOWER ASPECTS OF LOWER JAW OF greaved tortoise. (From Gray, Proc. Zool. Soc., 1870., knob-like condyle with a corresponding cavity in the quadrate-bone, whereas in the preceding group the positions of the condyle and cup are reversed. The shell, which is always fully developed and forms a solid box, presents the peculiarity that both the carapace and the hinder part of the plastron are immovably welded to the bones of the pelvis; its upper and lower moieties thus having a bond of union which is totally lacking among the S-necked tortoises. Further, the vertebrae of the neck are furnished with pro- jecting lateral or transverse pro- cesses, which are absent from the latter group. In addition to these absolutely characteristic features, there are cer- tain other points connected with the anatomy of the side-necked tortoises which demand a brief notice. With the exception of one species, which lacks horny FRONT PORTION OF THE PLASTRON OF A SIDE-NECKED TORTOISE, WITH THE HORNY SHIELDS REMOVED. The thick lines indicate the boundaries of the shields. go TORTOISES AND TURTLES. shields on the shell, the whole of these tortoises are characterised by the presence of an intergular (i.gw) shield between the two gulars (gu) on the front of the plastron ; such intergular shield being, as we have seen, but very rarely present in the S-necked group. Very generally among the present assemblage one or more of the pairs of costal bones of the carapace may meet in the middle line, owing to the absence of some of the median unpaired series of bones; in certain cases the whole of the costals thus meeting, owing to the absence of all the neural bones. Whereas, in one family of the group the plastron contains the same nine bones as in the side -necked tortoises, in a second family there are eleven bony elements in this part of the shell, owing to the presence of an additional (mesoplastral) pair between the normal hyo- and hypo-plastral bones. The side-necked tortoises, of which the great majority may be included in the two families men- tioned above, are all of fresh-water habits, and at the present day are exclusively restricted to the Southern Hemisphere, while they are the only members of the order found in Australia and New Guinea. During the earlier portion of the Tertiary period they extended, however, into the Northern Hemisphere, and in the preceding Secondary period were abundantly represented in Europe. These facts show that the group is a very ancient one ; and by the presence of the additional mesoplastral elements in the lower half of the shell of some of its representatives it is allied to a third and totally extinct group, which dis- appeared before the close of the Secondary period. Matamata The extraordinary reptile depicted in the accompanying illustra- Tortoise. ^ion, anc[ known as the matamata (Chelys flmbriata), is the typical representative of the first of the existing families of the group — Chelyidce. The various genera included therein are collectively characterised by having the normal nine bones in the plastron, by the neck being incapable of complete retraction within the margins of the shell, and the absence of a bony temporal arch to the skull. Eight genera are included in the family, the range of which is restricted to South America, Australia, and New Guinea. The matamata, which is an American species inhabiting Guiana and Northern Brazil, and is the sole representative of its genus, is easily recognised by its broad and elongated neck, of which the sides are fringed with peculiar fimbriated pro- jections, and the depressed and triangular head terminating in a proboscis-like nose, and furnished with very small eyes. Not less characteristic is the equally depressed and much corrugated shell, in which the carapace bears three longitudinal ridges, subdivided into nodose protuberances by cross-valleys ; the horny shields of the same being extremely rugose, and marked with deep radiating striae. The EIGHT HALF OF THE CARAPACE OF THE BLACK STERNOTHERE, WITH THE HORNY SHIELDS REMOVED. SIDE-NECKED. TORTOISES. 9i vertebral shields are broader than long, and the hinder marginals are more or less strongly serrated, while there is a distinct nuchal shield on the front edge of the carapace. On the removal of the horny shields from the carapace, it is seen that only the last pair of costal bones meet in the middle line, owing to the presence of but seven neural bones. The plastron is narrow and deeply notched behind, the tail is very short, and the toes are fully webbed. In addition to the rows of fimbriated appendages on each side of the neck, there is a similar outgrowth of skin on the chin and larger pair of appendages above the ears. In colour the adult is uniform brown, but the young are prettily marked with bands of brown and yellow on the MATAMATA TORTOISE {\ nat. size). chin and neck, while the shell is ornamented with black and yellow spots. The species is of comparatively large size, the shell attaining a length of 15 inches. Unfortunately, but little is known as to the mode of life of this strange tortoise. When in its native element, the warty appendages on the neck float in the water like some vegetable growth, while the rugged and bossed shell strongly resembles a stone; and it is thus probable that the whole appearance of the creature is advantageous either in deluding its enemies or in attracting to it the animals on which it feeds — the latter being the more likely hypothesis. Although it appears that the matamata will occasionally eat vegetable substances, its chief food consists of fish, frogs, and tadpoles, some of which may probably be attracted within reach 92 TORTOISES AND TURTLES. by mistaking the appendages on the neck for plants or animals on which they feed. The matamata is, however, stated to capture some of its prey by swimming swiftly among water-plants, diving immediately that a fish or frog is seized in its beak. In captivity this tortoise is sluggish, frequently dying after a few weeks through refusal to feed. Snake-Necked The snake-necked tortoises, of which there are two South American Tortoises, species (Hydromedusa maximiliani and tectifera), agree with the matamata in their long necks and weak jaws, but differ in their smooth shell, the absence of a proboscis to the nose, and the presence of only four claws on each ,— V r*N- SNAKE-NECKED TORTOISE (£ nat. size). foot — the matamata having five claws on the fore-feet and four on the hinder pair. The flattened shell in the young state has an interrupted median ridge, and presents the unique peculiarity that the broad nuchal shield of the carapace is placed behind the first pair of marginals (which consequently meet in the middle line), and thus simulates a sixth vertebral shield. The figured species (H. tectifera), which ranges from Southern Brazil to Buenos Aires, has a shell measuring about 8 inches in length, and its feet largely webbed. In colour, the carapace is dark brown and the plastron yellowish, with brown spots in the young ; the head and neck being olive, with a curved white streak on each side of the throat, and a broader white band, edged with black, running along the sides of head and neck. SIDE-NECKED TORTOISES. 93 Nocturnal and carnivorous in their habits, the snake-necked tortoises appear to agree in their general mode of life with the majority of fresh-water species. During the daytime they are generally to be found lying asleep on some dry spot near the water, with the neck bent on one side, and the head, like the limbs and tail, retracted within the margins of the carapace. When disturbed, the head and neck are, however, shot out with marvellous rapidity, reminding the observer of the sudden dart of a snake. Australian Long- In Australia and New Guinea the place of the preceding group Necked Tortoises. is taken by another genus of long-necked tortoises, technically known as Chelodina, the members of which may be recognised by the presence of a normally placed nuchal shield on the carapace, coupled with the circumstance that the inter- gular shield of the plastron, instead of being placed between the gulars, as in the figure on p. 89, is situated behind the latter, which consequently meet in the middle line. The ver- tebral horny shields are longer than broad, and the whole of the shields remarkable for their extreme thinness. On remov- ing the latter from the carapace, it will be found that, owing to the absence of neural bones all the pairs of costal bones meet in the middle line, — a peculiarity shared with one American, and two other Australian genera of the family. There- are four species of these long-necked tortoises, three of which are found in Australia, while the fourth is Papuan. In addition to the foregoing, there are four other genera belonging to the family under consideration, collectively distinguished by their shorter necks, the length of which is inferior to that of the back. Of these the American Rhinemys, Hydrastis, and Platemys are characterised by the narrow anterior extremity of the lower jaw, and by the first vertebral shield of the carapace being wider than either of the others. The second of these genera, of which a member is represented in the accompanying figure, is by far the most numerous in species; and is noteworthy on account of being represented by a fossil species in the Eocene deposits of India. The third genus differs from the other two in the absence of neural bones to the carapace. On the other hand, the two Australian genera — Emydura and Elseya, — both of which present the feature last mentioned, are distinguished by the broad anterior extremity of the lower jaw, and by the first vertebral shield of the carapace not exceeding the others in size. Oreaved The tortoises which may be conveniently designated by a Tortoises, translation of their scientific title (Podocnemis) — so named on account AN AMERICAN SIDE-NECKED TORTOISE (Hydmspis). Other Genera. 94 TORTOISES AND TURTLES. of the presence of a pair of large shields on the outer side of the hind-foot of the typical species — bring us to the second family of the group under consideration. This family (Pelomedusidce), which contains three genera, and is now confined to Africa, Madagascar, and South America, is broadly distinguished from the last by having eleven elements in the plastron, owing to the presence of a pair of meso- plastral bones ; while the neck is completely retractile within the margins of the shell. The skull differs from that of the preceding family in having a bony temporal arch, as shown in the figure on p. 89 ; while it lacks the distinct nasal bones generally found in the former. The largest and best known representative of the whole family is the giant Amazonian tortoise (Podocnemis expansa), which considerably exceeds in size all GIANT AMAZONIAN TORTOISE (\ liat. size). other members of the entire group, having a shell which may measure as much as 30 inches in length. It belongs to a genus including seven existing species, of which six are South American, while the seventh is an inhabitant of Madagascar. This extremely anomalous distribution is to some extent explained by the occurrence of a fossil representative of the genus in the Eocene strata of India, which probably indicates that these tortoises were at one time widely spread. As a genus, these tortoises are characterised by the skull having a roof over its temporal region, coupled with the presence of five claws on the fore-feet, and four on the hinder pair, and likewise by the circumstance that the mesoplastral bones are small and confined to the edges of the plastron, so that they are widely SIDE-NECKED TORTOISES. 95 separated from one another in the middle line. The toes are broadly webbed, and the tail is remarkable for its extreme shortness. The figured species, which inhabits tropical South America to the eastwards of the Andes, and is extremely abundant in the upper part of the Amazonian system, has the shell expanded posteriorly, and much depressed in the adult, although at an earlier stage it has a roof -like form. The chin is furnished with two small wart-like appendages ; and the hind-foot characterised by the presence of two very large shields on its outer side. In colour, the upper shell is brown or olive, with darker markings, while the plastron is yellowish, spotted with brown ; the young being olive above and yellow beneath, with some yellow spots on the head. All the other members of the genus are of greatly inferior dimensions ; a second Amazonian species (P. sextuberculata), having a shell of scarcely more than a foot in length, and being distinguished from its larger relative by the presence of only a single wattle on the chin. The best account of the habits of these tortoises is the one given by Humboldt, who speaks of the large species by its native name of arran. On the Orinoco, according to this account, the period of egg-laying coincides with that of the lowest level of the waters of the river, or from the end of January till the latter part of March. During January the tortoises collect in troops, which soon leave the water to bask on the warm banks of sand exposed by the lowering of the river. Throughout February they may be found on such banks during the greater part of the day ; but early in March the several troops collect in larger bodies, and then make their way to the comparatively few islands where the eggs are habitually deposited. At this time, shortly before the egg-laying commences, thousands of the tortoises may be seen arranged in long strings around the shores of the islands in question, stretching out their necks, and holding their necks above water, in order to see whether there is anything to prevent their landing in safety. As the creatures are exceedingly timid, and especially averse to the presence of human beings or boats, the Indians, to whom the harvest of tortoise- eggs is of the utmost importance, take every precaution to prevent them being disturbed, posting sentinels at intervals along the banks, and warning all passing boats to keep in the middle of the river. When the tortoises have landed, the laying of the eggs takes place at night, and begins soon after sunset ; the females digging holes of some three feet in diameter and two feet in depth, by the aid of their powerful hind-limbs. So great is the contention for space, that one tortoise will frequently make use of a pit dug by a neighbour, and in which one set of eggs has already been deposited, although not yet covered over with sand ; two layers of eggs thus occupying one area. The crowding and jostling of the reptiles necessarily leads to an immense number of eggs being broken, which is estimated at a fifth of the whole ; the contents of the fractured shells in many places cementing the loose sand into a coherent mass. The number of tortoises on the shore during the night being so large, many of them are unable to complete the work of egg-laying before dawn; and these belated individuals become quite insensible to danger, continuing there even in the presence of the Indians, who repair to the spot at an early hour. The great assemblage of these Chelonians takes place on one particular island 96 TORTOISES AND TURTLES. in the Orinoco, hence known as the Boca de la Tortuga ; and according to native accounts, no other spot is to be met with on the river from its mouth to its junction with the Apure, where eggs can be found in abundance. On the island in question, the number of eggs deposited is enormous ; a large stretch of smooth sandy beach being underlain with an almost continuous layer. To determine the position and extent of the deposit, a long pole is thrust down at intervals into the sand; the sudden want of resistance to its descent proclaiming when the loose layer containing the eggs has been reached. According to measurements taken by Humboldt, the stratum extended to a distance of one hundred and twenty feet from the water, and averaged three feet in depth. The whole is regularly parcelled out among the Indians, who proceed to work the layer with the regularity of miners. The earth having been removed, the eggs are carried in small baskets to the neighbouring encampment, where they are thrown into long wooden troughs of water. Here they are broken and stirred up with shovels, and the mass then left in the sun till all the oily matter has collected at the surface, whence it is continually ladled off, and taken off to be boiled over a quick fire. The result of this process is a limpid, inodorous, and scarcely yellow substance, known as " turtle- butter," which can be used for much the same purposes as olive-oil. In spite of the enormous quantity of eggs thus taken, numbers are hatched, and Humboldt saw the whole bank of the Orinoco swarming with small tortoises of an inch in diameter, that escaped only with difficulty from the pursuit of the Indian children. All these tortoises are vegetable feeders ; and the females greatly exceed the males in size. On the upper Amazon the large species, according to Bates, is captured either by means of nets or by shooting with arrows. On such occasions, after the net is set in a semicircular form at one extremity of a pool, the rest of the party spread themselves around the swamp at the opposite end, and begin to beat with poles in order to drive the tortoises towards the middle. This process on the occasion referred to " was continued for an hour or more, the beaters gradually drawing nearer to each other, and driving the hosts of animals before them ; the number of little snouts constantly popping above the surface of the water showing that all was going on well. When they neared the net, the men moved more quickly, shouting and beating with great vigour. The ends of the net were then seized by several strong hands and dragged suddenly forwards, bringing them at the same time together, so as to enclose all the booty in a circle. Every man now leapt into the enclosure, the boats were brought up, and the turtles easily captured by the hand and tossed into them." Altogether, about eighty individuals were captured in the course of twenty minutes or so. In shooting tortoises, the arrow employed has a strong lancet-shaped steel point, fitted to a peg which enters the tip of the shaft. To the latter the peg is secured by a hank of twine some thirty or forty yards in length, and neatly wound round the body of the arrow. When a tortoise is struck, the peg drops out from the shaft, and is carried down by the diving animal, leaving the latter floating on the surface. Thereupon the sportsman paddles up to the arrow, and proceeds to " play " his victim until it can be drawn near to the surface, when it is struck with a second arrow, after which, by the aid of the two cords, it can be safely drawn ashore. In many villages on the Amazon every house has a pond, in which a number of these tortoises are kept for food. SIDE-NECKED TORTOISES. 97 The other two genera of the family — Pelomedusa and Sterno- therus — differ from the first by the absence of a bony roof to the temporal region of the skull, and likewise by the presence of five claws in both the front and hind-feet. Whereas, however, the former has the mesoplastral elements of the plastron small and similar to those of the greaved tortoises, in the latter they are as well developed as the other elements of the plastron, meeting in the middle line. Pelomedusa is represented by a single species common to Africa and Madagascar, but of the six species of Sternotherus, five are exclusively African, while the sixth inhabits both Eastern Africa and Madagascar. The right half of the upper shell of one of the species is represented on p. 90. A remarkable Chelonian (Carettochelys insculpta) from the Fly Fly River Turtle. . v -, i . River, New Guinea, differs from all other members of the group, in the absence of horny shields on the shell and the conversion of the limbs into paddles, each of which carries but two claws. The neck is not retractile. In the carapace there are six very small neural bones, which are not in contact with one another, thus allowing each pair of costals to meet in the middle line ; and the plastron has only the usual nine bones. A wavy sculpture ornaments the whole of the external surface of the shell, which attains a length of about 18 inches. The head is large, and the tail relatively short. The species, which represents a separate family (Carettochelyidce), is still very imperfectly known; and it has been suggested that it does not belong to this group at all. It is not improbable that a chelonian (Hemichelys), from the Eocene rocks of India, indicates a second member of the same family, as its shell was similarly devoid of horny shields. Australian Probably the most aberrant members of the whole order were Horned Tortoises, certain gigantic tortoises (Miolania) from the superficial deposits of Australia, characterised by the presence of several pairs of horn-like protuberances on the skull, and also by the investment of the tail in a bony sheath, recalling that of the armadillos. Unfortunately, the shell of these strange reptiles is known only by fragments; but, from the conformation of the bones of the feet, we are FRONT VIEW OP SKULL OF HORNED TORTOISE. • enabled to say that they were terrestrial, while the structure of the palate indicates that they were herbivorous. They clearly constitute a fourth family (Miolaniidce) of side-necked tortoises. Extinct European The Secondary rocks of Europe contain the remains of a number Genera. 0£ extinct tortoises which may be referred to a fifth family (Plesio- chelyidce) of the group. While agreeing with the existing Chelyidce in having but nine bones in the plastron, these extinct forms differ by the much greater thickness of their shells, and also by the circumstance that only one of the lower bones of the pelvis is welded to the upper surface of the plastron, whereas in the existing families both are thus united. Abundant in both the Oolitic and Wealden rocks, the majority of these tortoises are referred to the genus Plesiochelys, although some, as the one of which the carapace is represented in the figure on the next page, are separated as Hylcechelys, being distinguished by the enormous width of the vertebral shields, in which the breadth may be three times the length. Nothing VOL. V. — 7 98 TORTOISES AND TURTLES. approaching this conformation is to be met with among living representatives of the order. Generalised Certain extinct tortoises, such as Pleurosternum from the Cneionians. Purbeck Oolite of Swanage, and Baena of the Eocene rocks of the United States, indicate the existence of an extremely generalised group of the order Amphichelydia, presenting many characters common to the existing S-necked and Side - necked groups, and which may have been the ancestral stock of both the latter. All have eleven bones in the plastron, owing to the presence of mesoplastrals, and an inter- gular shield, but the pelvis may or may not be connected with the plastron. In the first of the genera named, the mesoplastral bones extend right across the shell to meet in the middle line, and one of the bones of the pelvis articulates to a smooth oval facet on the plastron. On the other hand, in the second genus, the mesoplastral bones are incomplete, as in the existing greaved tortoises, and there is no union between the pelvis and the plastron. Since it is probable that the plastron of the Chelonians has originated from a system of abdominal ribs similar to those of the tuateras (Chapter VI.), it is interesting to notice that these generalised tortoises had a larger number of plastral elements than are to be found in the majority of the existing representatives of the order. IMPERFECT CARAPACE OF WIDE-SHIELDED WEALDEN TORTOISE. The Soft-Tortoises. Family TRIONYGHID^. The last group of the order comprises the soft river-tortoises, now confined to the warmer regions of Asia, Africa, and North America, but which, during the middle portion of the Tertiary period, appear to have been extremely abundant in the rivers of England and other parts of Europe. The whole of these tortoises are included in a single family which forms a group of equivalent value to the S-necked and Side-necked sections; and it is not a little remarkable that while in the greater part of their organisation they approximate to the former group, in certain features connected with the skull they come nearer to the latter. The most striking peculiarity of the soft-tortoises is to be found in' the nature of their shells, SOFT RIVER TORTOISES SOFT- TORTOISES. 99 which are covered with a raised sculpture of variable form, and are quite devoid of horny shields. The lower shell, or plastron, is always very imperfectly ossified, and completely separate from the carapace ; while the carapace never has a complete series of marginal bones, and passes at its borders into a soft expansion of skin, from which the name of the group is derived. If marginal bones occur at all, they are confined to the hinder border of the shell, and are unconnected with the ribs ; having, in fact, nothing in common with the bones so named in other tortoises, and being doubtless of independent origin. In being unconnected with the plastron, the pelvis resembles that of the S-necked group, and the head is retracted by a similar S-like flexure of the neck in a vertical plane. In regard to the mode of articulation of the lower jaw with the skull, and likewise in the presence of a notch in the hinder border of its tympanic ring, the soft-tortoises again resemble the group last mentioned; although in the general form of the skull and the conformation of the palate they come nearer to the Side-necked group. A distinc- tive peculiarity of the skeleton is to be found in the presence of at least four joints in the fourth toe of each foot. Externally, the soft-tortoises are characterised by their long necks, which, together with the head, can be completely withdrawn into the shell, and also by the proboscis-like snout, and the thick fleshy lips concealing the jaws. The ear is completely concealed; and each foot, as indicated by the scientific name of the group, has but three claws, which are borne by the three inner toes. As a rule, the colour of the skin is greenish olive, with yellow or orange spots, passing into streaks on the under surface of the head ; while some species have a few much larger eye-like spots on the back of the shell. Although the whole of the soft-tortoises are included in a single Typical Genus. ° .... . family, they are arranged in six distinct genera, three of which are nearly allied to one another, as are likewise the remaining three among themselves. The first and largest genus, Trionyx, contains fifteen living species, with a distribu- tion coextensive with that of the family. These are characterised by the absence of a fold of skin on the hinder part of the under shell, beneath which the leg may be concealed, by the sculpture on the shell being generally in the form of wavy raised lines, and by the hyo- and hypoplastral bones of the lower shell remaining distinct from one another. In the skull, as shown in the figure on p. 89, the sockets of the eyes are placed relatively far back, and widely separated from the aperture of the nose. Among the better-known species we may mention the Gangetic soft-tortoise (T. gangeticus), now confined to the river system from which it takes its name, but formerly found, as shown by fossil specimens, in the Narbada; the length of the shell and fleshy disc reaching as much as 2 feet. Like all the Old World representatives of the genus, this species has eight pairs of costal bones in the carapace; while it belongs to a subgroup characterised by having two neural bones between the first pair of costals, and by the absence of a pronounced ridge in the middle of the upper surface of the extremity of the lower jaw. The soft-tortoise of the Nile (T. triunguis), ranging over Africa and Syria, and attaining still larger dimensions, belongs to a second subgroup, distinguished by having only a single neural bone between the first costals ; while Phayre's soft- tortoise (T. phayrei), of Burma, may be taken to represent a third section differing from the last by the presence of a median ridge in the front of the lower jaw. On IOO TORTOISES AND TURTLES. the other hand, all the American soft-tortoises, of which T. ferox is a well-known example, differ by having only seven pairs of costal bones. Numerous representa- tives of the genus occur in the Miocene and Eocene strata of Europe, as well as in the Tertiary rocks of India and the United States. Two other members of the first subfamily, confined to Asia, represent as many genera. Of these Cantor's soft-tortoise (Pelochelys can- tori), from India, Burma, and Malay ana, has the sockets of the eyes placed more anteriorly than in the type genus. This forward position of the eye-sockets is still more marked in the much elon- gated skull of the great Indian chitra (Chitra indica), where they are placed close up to the nose. Granulated soft- The three remaining Tortoises, genera of the family are characterised by the sculpture of the shell generally taking the form of small pustules, and thus resembling shagreen ; while the hyo- and hypoplastral bones of the lower shell are united ; and there is a flap of skin on each side of the under surface, beneath which the hind-limbs can be concealed. All the forms are confined to the Old World ; and while one of the three genera is Indian, the other two are African. The Indian genus Emyda is readily characterised by the presence of a complete series of neural bones in the carapace, coupled with a semicircle of marginal bones at its hinder extremity. In neither of the three living species does the length of the shell and its soft disc exceed 10 inches, but much larger fossil forms are found in the Pliocene rocks of India. Both the African genera lack marginal bones, but whereas in one (Cycloderma) there is a full series of neural bones to the carapace, in the other (Cyclanorbis) these form an incomplete and interrupted series. All the soft-tortoises are thoroughly aquatic, most of them but rarely leaving the water except for the purpose of laying their eggs, and in consequence of these habits very little is known as to their mode of life. Although confined as a rule to rivers, a few of the species frequent estuaries, and Cantor's soft-tortoise has been found some distance out at sea. Occasionally, again, specimens of the Indian granulated soft-tortoises have been met with wandering on land far from the neighbourhood of water. Fiercer and more spiteful than any other members of the Chelonian order, these tortoises, owing to a peculiarity in the structure and mode of articulation of some of the vertebras of the neck, have the power of darting out the head with inconceivable rapidity, the great Indian chitra being facile princeps in this respect. Owing to this habit the larger species are dangerous creatures to approach incautiously, as their bite SOFT-TORTOISE. Habits. PLESIOSAURS. is very severe ; and the natives are not unfrequently bitten by them in India and Burma whilst bathing. All the members of the typical genus, together with Cantor's soft-tortoise and the chitra, are known to be carnivorous, and it is commonly believed that the same is the case with the other members of the group. According, however, to Dr. J. Anderson, this is incorrect with regard to the granulated soft-tortoises of India, which he expressly states to be exclusively vegetable and grain-feeders. The larger species probably feed both on fish and other aquatic animals, and on the flesh of such carcases as may be floating in the rivers they inhabit. In correlation with their asserted herbivorous habits, the small granulated species do not snap and bite after the manner of their larger cousins. On shore, according to the observer last mentioned, when left to themselves, these species will slowly and cautiously extend their necks, and when approached, instead of attempting to escape, withdraw rapidly into their shells, of which the upper and lower anterior margins then meet. It is stated that all the species are chiefly nocturnal, remaining during the daytime partially or completely buried in the mud at the bottom of the water, and not beginning to swim till sundown. Such species as inhabit marshes or swamps, liable to be dried up during the hot season, bury themselves in the mud, at no great depth below the surface, during the period of drought. As these tortoises are known to remain frequently for a period of from two to ten hours, and occasionally as much as fifteen hours, beneath the water, without coming to the surface to breathe, it is obvious that they must have some special means of oxygenating their blood. It is probable, indeed, that certain filamentous appendages of the mucous membrane of the throat found in these tortoises subserve the office of gills, and thus enable the blood to be renovated by means of the atmospheric air dissolved in the water they inhabit. With regard to their breeding-habits, it appears that the females of the granular shelled species scrape a shallow hole in the mud, in which the eggs are laid and then carefully covered up, the eggs themselves being round, and about an inch in diameter. The Plesiosaurs or Long-Necked Marine Lizards. Order Sauropterygia. Strikingly different in appearance as are the skeletons of the members of the two groups, it appears that, on the whole, the nearest allies of the tortoises and turtles are those extinct reptiles known as plesiosaurs, or long-necked marine lizards, whose range in time embraced the whole of the great Secondary period, during which were deposited the vast series of strata extending from the Chalk downwards through the Oolites to the Lias and Trias. These reptiles agree with the tortoises in that all or nearly all of the ribs of the back are articulated to the vertebrae by single heads, and in the absence of hook-like (uncinate) processes to the ribs, as well as in the want of a breast-bone or sternum. In the skull the quadrate-bone is immovably fixed, and the palate more or less completely closed. Both groups have the lower bones of the pelvis expanded into large flat plates, and there is also a similarity in the structure of the bones of the limbs. Whereas, however, the tortoises have the upper surface of the body covered 102 PLESIOSAURS. with a shell, and the lower aspect of the same protected by a plastron, the plesiosaurs were entirely naked, the plastron being represented by a numerous series of abdominal ribs, each composed of three pieces, forming a forwardly- directed angle. The skull differs from that of the crocodiles in having but one (lower) temporal arch ; and the jaws are furnished with a number of pointed and grooved teeth, implanted in distinct sockets; one of such teeth being figured on p. 5. The neck was generally much elongated, and its vertebrae differ from those of crocodiles in that their ribs which may have either single or double restored skeleton of a plesiosaur (greatly reduced). heads, are articulated only to the body of each vertebra (as shown in the accom- panying figure); those of crocodiles always having two heads, of which the lower is articulated to the body, and the upper to the arch of the vertebra. Throughout the backbone the bodies of the vertebras have either nearly flat or slightly cupped articular surfaces ; and in the region of the back each pair of ribs is articulated to a process arising from the arch of each vertebra, instead of from a facet placed at the junction of two vertebras, as in the tortoises. Although there are other interesting features in these reptiles, those mentioned distinguish them from crocodiles and dinosaurs on the one hand, and tortoises and turtles on the other. With regard to the various groups into which the order is divided, it may be mentioned that in the typical forms, constituting the family Plesiosawidce, the limbs, as shown in the figure on p. 102, are converted into flattened paddles, with a shortening of the bones of the upper segments, and an increase in the number of bones corresponding with those of the toes of ordinary reptiles. In the true plesiosaurs (Plesiosaurus) of the Lias, the ribs of the neck were articulated to the vertebras by two heads ; whereas in the later cimoliosaurs (Cimoliosaurus) of the Oolites and Chalk, such ribs, as shown in the figure of a neck-vertebra, were single-headed. Some of these creatures were of huge size, attaining a length of between 30 and 40 feet ; certain of the species UPPER SURFACE OF THE SKULL OF THE SIMOSAUR, OR TRIASSIC PLESIOSAUR. n, nostrils ; or, eye-sockets ; st, temporal fossae (i nat. size). — From Gaudry. PLESIOSA UPS. 103 from the Cretaceous strata having a neck much exceeding the body and tail in length, and containing as many as forty vertebrae. Marine and carnivorous in their habits, these formidable creatures probably lurked in shoal-water, from whence they darted their long necks to seize passing fishes in their jaws. In the groups mentioned the head was comparatively small, but in the huge pliosaurs (Pliosaurus) of the upper Oolitic strata the skull was of enormous size, attaining in some instances a length of 6 feet, and the neck proportionately short and thick. Their teeth had more or less triangular crowns, and in some cases, inclusive of the root, measured quite a foot in length. As is the case with ail the higher aquatic Vertebrates, there is evidence to show that the plesio- saurs were originally derived from land animals ; the repre- sentatives of the group found in the earlier (Triassic) Secondary rocks hav- ing limbs departing much less widely from the ordinary type, and bearing claws at the extremities of their digits. In the small lariosaur, which measured about a yard in length, the limbs appear to have been somewhat intermediate in structure between the clawless paddles of the true plesiosaurs and those of more ordinary reptiles; and the creatures were probably amphibious in their habits, spending part of their time on land, and part in the water. In the allied nothosaurs and simosaurs the limbs were better adapted for walking, from which we may infer that their owners were still more terrestrial in their habits. FRONT AND SIDE-VIEWS OF A NECK-VERTEBRA OF A PLESIOSAURIAN. pr.z, mdpt.z, anterior and posterior articular surfaces of the arch ; co, rib. UPPER ASPECT OF THE SKELETON OF THE LARIOSAUR, A SMALL PLESIOSAURIAN. CHAPTER IV. Scaled Reptiles — Lizards and Chameleons, — Order Squamata ; Suborders Lacertilia and Rhiptoglossa. Skull. Although in popular language the term lizard is applied to any four-legged reptile, exclusive of turtles and crocodiles, in scientific usage it is more convenient to restrict it to those members of the great group of scaled reptiles which do not come under the designation of either chamseleons or serpents, whether they are provided with legs, or whether they lack those useful appendages. Formerly, indeed, lizards and chamaeleons were regarded as constituting an order by themselves quite apart from serpents, but the two groups are now known to be so intimately connected as to render any such division inadmissible ; and they are accordingly here placed in a single order, known as scaled reptiles, or, technically, Squamata. Structurally, this ordinal group differs very widely indeed from any of those hitherto treated, and as it is essential to gain a correct idea of such structural differences, they may first bo taken into consideration. Taking their name from the coat of overlapping horny scales with which they are generally invested, the scaled reptiles are primarily distinguished from all the foregoing groups by the circumstance that the quadrate-bone is more or less movably articulated to the skull, and has its lower end projecting freely therefrom, instead of being immov- ably wedged in among the other bones. To this primary point of distinction it may be added that the lower temporal arch of the skull is wanting, so that there is no bony bar connecting the lower end of the quadrate- bone with the upper jaw, as there is in the crocodiles ; the absence of this bar being well shown in the figure of a lizard's skeleton. Then, again, the palate, instead of being more or less completely roofed over by bone, is largely open, its bones taking the form of long bars. In some lizards, as in the one of which the skeleton is figured, the upper surface of the skull is covered by bone, so that the temporal fossae are roofed LEFT SIDE OF THE VERTEBRA OF A SNAKE. over. Ribs and Vertebrae. Another important feature of the order is to be found in the circumstance that the ribs in the region of the back are single-headed, and are articulated to the backbone by means of a facet (d) situated on the body of each vertebra. This feature at once distinguishes the order from the crocodiles and dinosaurs, in which the ribs are two-headed, and in the back articulate to a ROUGH-TAILED AGAMA BASKING. LIZARDS. 107 long process arising from the arches of the vertebrae ; from the tortoises, where the single-headed ribs articulate at the junction between the bodies of two vertebras ; and from the plesiosaurs, in which the single-headed ribs of the back are articulated to processes or facets on the arches of the vertebras. In most of the members of the order the body of each vertebra has a cup in front and a ball behind, by which it articulates with the adjacent segments of the column — an arrangement paralleled among modern crocodiles. In some lizards, and in all snakes, the vertebras, as shown in the figure on p. 6, have additional surfaces on their arches for mutual articulation, thus communicating additional flexibility, and at the same time strength to the backbone. Another important feature in which the order differs from all Other Characters. , „ _ i-i-t the preceding ones, is the absence or any system of true abdominal ribs, or of their equivalent, a plastron, on the inferior surface of the body. As regards the teeth, these differ from those of the orders hitherto considered in that, instead of being implanted in separate sockets, they are firmly soldered to the bones of the jaw. . In some cases they are attached to the very summit of the jawbones, when the dentition is said to be acrodont ; while in others they are affixed to one of the side- walls of the free edges of the jaws, the term pleurodont being then employed. Another divergence from both crocodiles and tortoises is to be found in the vent opening by a transverse aperture, whereas in the former group it is longitudinal, and in the latter either circular or longitudinal. Finally, in those forms in which the bones of the chest attain their fullest development, there is a breast-bone or sternum, a pair of collar-bones or clavicles, and a median T-shaped interclavicle. Special The above being the leading characters of the entire order of Characters of scaled reptiles, it remains to consider how the lizards (Lacertilia) are Lizards. ^Q -j^ distinguished from the other two suborders into which the existing members of the assemblage are divided. Externally, by far the greater number of lizards are four-limbed reptiles of a crocodile-like appearance, with the head, neck, body, and tail well distinguished from one another, and if we had these alone to deal with, there would be no sort of difficulty in distinguishing between a lizard and a snake. The matter is, however, somewhat complicated by the circum- stance that certain lizards, like the familiar slow-worm, lose all external traces of limbs, and assume an elongated snake-like form, with the head passing imperceptibly into the body without the intervention of a distinct neck, and without any external indication of where the body ends and the tail commences. Externally, such snake- like lizards are very difficult to distinguish from snakes, but on opening the mouths of the former it will be found that the tongue cannot be withdrawn into a sheath at its base, as is always the case with the latter. Further help in discriminating between the two is afforded by the circumstances that whereas snakes have neither eyelids nor external ear-openings, both these are usually, although not invariably, present in the limbless lizards. As additional distinctive features of the present group, by means of which they can be distinguished both from snakes on the one hand and from chamseleons on the other, the following points may be noticed. In all lizards the two branches of the lower jaw are united at the chin by means of a bony suture ; while in all the species furnished with limbs collar-bones are present ; and when the limbs are absent, some traces of the bones forming what is known 108 LIZARDS. as the shoulder-girdle persist. In form the tongue is flattened, and, as already- said, cannot be withdrawn into a basal sheath, although such a sheath may be present. In most of the members of the suborder the upper surface of the body is clothed with the overlapping scales characteristic of the order in general, these scales being in some cases underlain by bony plates ; but in most geckos the upper scales are granular, although sometimes juxtaposed. Numbers and Numerically, lizards are by far the most abundant of all reptiles Distribution. afc i^q present day, the total number of species not falling far, if at all, short of one thousand seven hundred, which are arranged under twenty distinct families. In this abundance at the present day, coupled with the specialised features of the greater part of their organisation, lizards may be regarded as occupying a very similar position in the reptilian class to that held by the perching birds in the preceding class. With the exception of the polar and sub- polar zones, lizards are distributed over the whole globe, ranging in some districts from the level of the sea to the limits of eternal snow, and found alike in fruitful SKELETON OF LIZARD. and barren districts, in the neighbourhood of water, and in the most arid deserts. Whereas, however, in the colder regions they are poor in species and small in size, it is in the tropics and subtropical regions that they attain their maximum development, as regards numbers, bodily size, richness of coloration, and peculiarity of form. As regards their distribution over the surface of the globe, lizards present a most remarkable difference from what obtains among Amphibians (frogs, newts, etc.), and, to a less degree, among tortoises. For instance, whereas Amphibians, and to some extent tortoises, have their distributional areas defined equatorially, such lines of division, in the case of the present group, must be drawn meridionally. Thus, in the case of Amphibians, one great distributional province includes Europe, Asia, and North America, and the second embraces the regions lying south of the Equator ; whereas in the case of lizards one area marked by peculiar forms will include the Old World and Australia, and the other will comprise the whole of America. As has already been noticed, the distribution of tortoises approximates to the former type, all the side-necked group being confined to the Southern Hemisphere. Again, we find that whereas Tropical Africa is closely related to HABITS. 109 Tropical India as regards its Amphibians, while Australia and Africa are near akin to South America in regard to their tortoises, in respect of lizards there is no close connection between India and Africa, but an intimate relationship exists between India and Australia, where members of the same genera occur ; while the Australian lizards are totally unlike their South American cousins. As might have been expected from their great numerical preponderance at the present day, lizards appear to be a comparatively modern group, their remains being rare in the lower Tertiary deposits, while in the Secondary period they are only known by a few species from the rocks of the Cretaceous epoch. That the group has originated from the tuateras, which were so abundant in the earlier strata of the Secondary period, may be regarded as most probable. Turning to their mode of life, we find that while a few members Habits. „ of the order resemble crocodiles, in spending the greater portion of their time in water, visiting the land only for the purposes of feeding, sleeping, or basking in the sun, by far the great majority of lizards are essentially land- animals, avoiding even damp situations. Although some inhabit trees, the greater number dwell either on the ground or among the clefts of rocks ; the conformation of the body generally giving some indication of this diversity of habitat. Among the land forms, for instance, those with depressed bodies are generally to be found in open sandy deserts, where they seek shelter either beneath stones or in holes ; whereas such as have the body compressed are more usually dwellers among bushes or in trees. Those, again, in which the body is more or less cylindrical, are in the habit of secreting themselves in the clefts of rocks or the chinks of tree- stems; while the snake-like kinds live on the ground, and those with a more worm-like form beneath its surface. The movements of the greater number of species — whether they live on the ground, among rocks, on trees, or on cliffs or walls — are agile in the extreme; and while the majority run with their bodies close to the ground, many habitually raise themselves up at times by resting on their hind-legs and tails, and are able to spring, either on the ground or from branch to branch, to a considerable distance after their prey. Of the arboreal species, some make use of their tails to aid in maintaining their hold, while others, together with cliff- and wall-hunting species, like the geckos, are enabled to run along the under sides of boughs, or to ascend vertical surfaces by the aid of their expanded and disc-like feet. The peculiar flying lizard is enabled to take long, flying leaps, supported by a parachute-like membrane borne by the expanded ribs ; while all the limbless species move somewhat after the manner of snakes, although making less use of the extremities of the ribs. The few aquatic forms swim and dive without the aid of webbed feet ; but many other kinds swim well if thrown into water. In many cases elegant and graceful in form, although at others rendered more curious than beautiful by the presence of spines or warts, lizards are pleasing rather than repulsive animals ; and, with the exception of the American heloderms, none are poisonous, although some will bite sharply. Few lizards possess a distinct voice, the majority merely uttering a low hiss ; some, however, especially among those whose habits are nocturnal — emit a clear, sharp cry, which has been likened both to the scream of a frog, and to the chirp of a cricket. Of their senses, the no LIZARDS. most acute is doubtless that of sight, next to which probably comes hearing. In regard to diet, a few lizards are strictly herbivorous, but the great majority are more or less completely carnivorous ; the larger kinds feeding on small mammals, birds and their eggs, other reptiles, and, more rarely, frogs and fish, as well as many descriptions of invertebrates. The smaller members of the order, on the other hand, are restricted mainly or entirely to an invertebrate diet, the great portion of which consists of insects, worms, and land-molluscs. Nearly all drink by rapidly protruding and withdrawing the tongue; dew affording sufficient moisture to those living on rock or in trees, while some kinds can exist for long periods, or even entirely without drinking. The species inhabiting the warmer regions, save those which are arboreal or aquatic in their habits, pass the hottest and driest season of the year in a state of torpor ; while those in colder regions regularly hibernate, such hibernation, in the case of some of the species inhabiting the continent of Europe, lasting for a period of from six to eight months. As regards their breeding-habits, the majority of lizards lay eggs, which may vary from two to thirty in number, and have generally a soft and leathery covering, although sometimes furnished with a hard calcareous shell. One peculiarity characterising the members of the order cannot be passed over before concluding these introductory remarks. This is the facility with which they are enabled to reproduce lost parts, and more especially the tail. As is well known, in many lizards, when handled, the tail breaks off without any rough usage, and in all or nearly all it will readily come in two if pulled when the creature is seeking to escape, this susceptibility to automatic fracture being due to a cartilaginous band across the middle of each vertebra of the tail in the case of the common lizard of England. Such missing portion of the tail is speedily reproduced, it may be double ; and whereas among the members of the typical family of the order, the scaling of the reproduced portion is like the original, in certain other forms this is by no means always the case. The remarkable circum- stance about the matter is that when the pattern of the scaling of such a new tail differs from the original, it always reverts to that characterising a less specialised and probably ancestral group. It is scarcely necessary to mention that in such an extensive assemblage as the present, only a comparatively small percentage of species, or even genera, can be mentioned, and these but briefly. The Geckos. Family Geckonid^E. Few creatures have given rise to a greater amount of fable and legend than the large group of lizards commonly known as geckos ; such legends being probably due to the nocturnal and domestic habits of these creatures, coupled with the sharp chirping cry from which they derive their name, and their curiously expanded disc-like toes. Absolutely innocuous, they have been credited from the earliest times with ejecting venom from their toes, and of poisoning whatever they crawled over ; while the teeth of one species have been asserted ,to be capable of leaving their impression on steel. Indeed, so intense is the dread inspired by these little GECKOS. in creatures, that in Egypt the lobe-footed, or fan-footed species is commonly termed abou-burs, or father of leprosy. Geckos, of which there are some two hundred and eighty species, distributed over all the warmer parts of the globe, although more numerous in the Indian and Australian regions than elsewhere, are for the most part small and plumply-built nocturnal lizards, characterised by their depressed form and dust-like coloration. The rather long and more or less flattened head is broad and triangular in shape ; the large eyes are characterised by the absence of movable lids, and by the pupil being, except in a few diurnal forms, vertical ; while the aperture of the ears is likewise in the form of an upright slit. Externally, the head is covered with minute granules, or small scales, and the body is devoid of a bony armour, and in most cases covered above with granules, and beneath with small overlapping scales. If we add to the above features that the tongue is either smooth or covered with villous papillae, and is short or moderate in length, and not ftt^s ''' & ** sheathed at the base, and that the bodies of the vertebras articu- late together by means of cup- shaped surfaces at both their extremities, we shall have said sufficient to distinguish the geckos from all other members of the suborder. As regards their other external characters, the neck is very short and thick, the body, although rounded, markedly depressed, and the tail, which is generally remark- ably brittle, usually thick and of moderate length, with its basal portion either cylindrical or laterally compressed, although it may be leaf -like, or even rudimental. In some cases the tail is known to be prehensile, and it is not improbable that it is frequently endowed with this power. The limbs are generally remarkable for their shortness, and are always provided with five toes each, the tips or sides of which may be more or less dilated. In those species inhabiting desert regions, the toes are of normal form, being often nearly cylindrical, and keeled on their lower surfaces ; but in the great majority of the members of the family, they are expanded either throughout their length or partially into adhesive discs, of which the under surface is formed by a series of movable symmetrical plates of variable form, by the aid of which the creatures are enabled to ascend walls and run across the ceilings of rooms. In some cases the claws are retractile, either within the plates of the discs, or into sheaths ; while in other instances the toes may be united by webs, which are not, however, for the purpose of swimming, all the geckos being land-lizards. The numerous teeth are small, and attached to one side of the summit of the jaw (pleurodont). LOBE-FOOTED GECKO. 112 LIZARDS. Lobe-Footed Gecko. The geckos being so numerous in species, which are arranged under no less than forty -nine genera, it is of course impossible in a work like the present to do more than notice a few of the better known or more striking. Among these, one of the most familiar is the little lobe- or fan-footed gecko (Ptyodactylus lobatus), of Northern Africa, Arabia, and Syria. This is one of two species belonging to a genus characterised by the toes (as shown in the Turkish gecko (nat. size). figure on p. Ill), being dilated at their summits, where they are furnished inferiorly with two diverging series of plates ; the digits being furnished with claws capable of retraction within notches in the front of the disc. The upper surface is covered with granules, among which are some small keeled tubercles ; the colour being greyish or yellowish brown above, with darker and light spots, and below uniform white. The length is a little over 5 inches. Equally well known is the Turkish gecko (Hemidactylus tur- Turkish. Gecko. * J . ,& . \ ... . cicus), represented in the figure above, which is likewise a small GECKOS. 113 species, inhabiting the countries bordering the Mediterranean and Red Seas, and also found in Sind. It belongs to a group of genera with dilated toes and compressed claws, and is specially characterised by the extremities of the toes being free, the plates on the under surface of the discs arranged in double rows, and the presence of some large shields on the under surface of the tail. Measuring not more than 4 inches in length, this species may be distinguished from the other FRINGED GECKO (nat. size). European geckos by the body being covered with from fourteen to sixteen longitudinal rows of warts, of which some are white and the others blackish, and like- wise by the hue of the upper-parts being greyish brown spotted with flesh-colour. It is, however, said to be able to change its colour according to circumstances, being of a shining milky white at night, and dark-coloured during the daytime. The genus to which it belongs comprises over thirty species, ranging over Southern Europe and Asia, Africa, Tropical America, and Oceania. vol. v. ii4 LIZARDS. A larger and more remarkable species is the one represented in the illustration on p. 113 (Ptychozoum homalocephalum), which is the sole member of a genus characterised by the presence of an expansion of skin along the sides of the body, continued as lobes on the tail, as well as by the toes being completely webbed, and the inner one devoid of a claw. Attaining a length of nearly 8 inches, this species has a distinctly ringed tail ; its colour above being greyish or reddish brown, marked with undulating dark brown transverse bands, and a dark streak extending from the eye to the first of the bands on the back. This gecko is an inhabitant of Java, Sumatra, Borneo, and the Malay Peninsula. The last member of the family we shall specially notice is the wall-gecko (Tarentola mauritanica), which is the Mediterranean representative of a small genus ranging from the countries bordering the Mediter- ranean to West Africa, and including one West Indian species. The genus is readily recognised by all the toes being dilated, and only the third and fourth furnished with claws. This species varies from rather less than 5 to somewhat more than 6 inches in length, of which one-half is formed by the tail. The sides of the neck and body, as well as the upper surface of the limbs, are ornamented with conical tubercles ; the back carries seven or nine longitudinal rows of larger and strongly-keeled tubercles ; and on the anterior half of the tail the ornamenta- tion takes the form of knobs with backwardly directed spines. The general colour of the upper-parts is greyish brown, with more or less distinct lighter and darker marblings, while a well-marked dark streak passes on each side of the head through the eye. With the exception of a certain number of species, the geckos, as already said, are nocturnal in their habits ; and many are remarkable for uttering shrill cries, probably produced by striking the tongue against the palate, which in some cases are compared to the syllables yeclco, checko, or told, and in others to the monosyllable tok. A South African sand -gecko is at times stated to occur in such numbers, and to produce such a din by its cry, as to render a sojourn in the neighbourhood well-nigh insupportable. As regards their habitat, geckos are very variable, some frequenting arid deserts, where they, in some instances, burrow in the sand ; others frequent wooded regions, living either among low bushes or on trees, and concealing themselves during the day beneath stones or the bark of the stems ; others again are found among rocks ; while a third group has elected to live among human dwellings, where some of its members have become as fearless and confiding as domesticated animals. Of the arboreal species, the frilled gecko is peculiar in having a parachute-like expansion of skin, which is used after the manner of that of the flying squirrels in aiding its owner to take long leaps from bough to bough. When at rest, the parachute is kept close to the sides of the body by the aid of its intrinsic muscles; and it is stated that this species, like several others, has the power of changing its colour according to the hue of the object in which it is resting. The species frequenting houses may be divided into those which resort to the interior, and those which are content with the outside. Of the latter, Sir J. E. Tennent writes that; in Ceylon, " as soon as evening arrives, geckos are to be seen in every house in keen and crafty pursuit of GECKOS. "5 their prey ; emerging from the chinks and recesses where they conceal themselves during the day, to search for insects that then retire to settle for the night. In a boudoir, where the ladies of my family spent their evenings, one of these familiar and amusing little creatures had its hiding-place behind a gilt picture-frame. Punctually as the candles were lighted, it made its appearance on the wall to be fed with its accustomed crumbs ; and, if neglected, it reiterated its sharp quick call wall-geckos (nat. size). of chic, chic, chit, till attended to. It was of a delicate grey colour, tinged with pink ; and having by accident fallen on a work-table, it fled, leaving part of its tail behind it, which, however, it reproduced within less than a month. ... In an officer's quarters, in the fort at Colombo, a gecko had been taught to come daily to the dinner-table, and always made its appearance along with the dessert. The family were absent for some months, during which the house underwent extensive repairs, the roof having been raised, the walls stuccoed, and the ceilings whitened. It was naturally surmised that so long a suspension of its accustomed habits would n6 LIZARDS. have led to the disappearance of the little lizard ; but on the return of its old friends, it made its entrance as usual at their first dinner, the instant the cloth was removed." Another Indian observer, Colonel Tytler, writing of these house-geckos states that although several, species "may inhabit the same locality, yet, as a general rule, they keep separate and aloof from each other; for instance, in a house the dark cellars may be the resort of one species, the roof of another, and the crevices in the walls may be exclusively occupied by a third species. However, at night they issue forth in quest of insects, and may be found mixed up together in the same spot ; but on the slightest disturbance, or when they have done feeding, they return hurriedly to their particular hiding-places." So far as is known, all the members of the family agree with the house-geckos in being insectivorous. With the exception of two peculiar New Zealand species producing living young, all the geckos appear to lay eggs, which are enclosed in a round and hard shell, and are generally two in number. A few peculiar geckos, assigned to three genera, and of which Hardwicke's gecko (Eublepharis hardwickei) is one of the best known examples, differ from the true geckos in being furnished with movable eyelids, and also in that their vertebrae are articulated together by means of cup-and-ball joints. Consequently, those eyelid geckos, as they may be termed, form a distinct family — JEublepharidce. The Scale-Footed Lizakds. Family Pygopodidje. To the ordinary observer it might well appear that the whole of the snake-like lizards, or those in which the body has become cylindrical and much elongated, and the limbs either rudimentary or wanting, would pertain to a single family. Such, however, is not the view of modern zoologists, who regard many of these abberrant members of the suborder as having been independently derived from several groups of fully limbed forms, and thus having but little relationship among themselves. Of these snake-like groups, one of the most remarkable is that of the scale-footed lizards of Australia and New Guinea, which form a family comprising six genera, all characterised by the retention of more or less well-marked rudiments of the hind-limbs, although the front pair have quite disappeared externally. According to the opinion of Mr. Boulenger, the scale-foots come nearest to the geckos, with which they agree in the essential characters of their skull, as they do in the nature of their tongue, the want of movable eyelids, and the vertical pupil of the eye ; although the latter character, as being variable in the geckos, cannot be regarded as of much importance. Apart from their external form, they differ from the geckos and thereby resemble the members of the next family in that the inner extremities of the collar-bones are not expanded into a loop-shaped form, while they are peculiar in that the number of bones entering into the composition of each half of the lower jaw is reduced from six to four. The small and numerous teeth are closely set, and have generally long, cylindrical shafts, and blunted summits ; although in the genus Lialis they are sharply pointed, swollen at the base, and backwardly curved, thus resembling those of the monitors. The hinder AGAMOID GROUP. 117 limbs are represented externally by a scaly flap, which is most developed in the genus to which the figured example belongs; the component bones may be felt more or less distinctly, and the skeleton of the common species shows five toe-bones. The common scale-foot (Pygopus lepidopus), which attains a length of about 20 inches, and has a tail twice as long as the head and body, is the typical repre- sentative of the few members of this family. The head is long, pointed at the snout, and scarcely separated from the body, being covered above with large symmetrical shields, and on the sides with small scales. The ear has an oblique oval aperture, and the rudimental immovable eyelids are circular and covered with minute scales. The cylindrical body is slender and of nearly equal thickness throughout, the scales on its upper surface, as in that of the long tail, being keeled. COMMON SCALE-FOOTED I.IZARD (§ nat. size). Larger in males than in females, the limbs have rounded extremities, and are enveloped in overlapping scales. In general colour, this lizard is coppery grey above, sometimes marked with three or five longitudinal rows of blackish dots or elongate spots; the under-parts being marbled grey, with the exception of the throat, which is white. Found both in Australia and Tasmania, and by no means uncommon in the Warmer northern parts of Victoria, this lizard, like its kin, is stated to have habits very similar to those of the blind- worm, although accurate observations on its mode of life are wanting. The Agamoid Lizards. Family AG AMID JE. The southern and eastern portions of the Old World are the home of a very extensive family of lizards, comprising thirty genera and over two hundred u8 LIZARDS. species, which may be conveniently termed agamoids, from the name of the typical genus. Agreeing with the preceding families in the characters of the tongue, and in the absence of bony plates beneath the scales, the agamoids resemble the scale- foots in the characters of their collar-bones ; bat are distinguished from all their allies in having teeth of the acrodont type, that is to say, situated on the very summit of the edges of the jaws. While the head is covered with small scales, the small eyes have circular pupils, and well-developed movable eyelids ; and the scales on the back are of the normal overlapping type. The thick tongue is either completely attached or only slightly free in front, and, at most, has but a very shallow notch in its tip. The teeth may be generally divided into three series, comparable as regards position with the incisors, tusks, and molars of mammals ; the latter being more or less compressed, and frequently furnished with three cusps, while the tusks, which may be one or two in number on each side, are of relatively large size in most cases, although occasionally absent. The fore-limbs are always well developed, and, except in one genus, five-toed. The absence of large symmetrical horny shields, both on the head and under-parts, is a noteworthy character of these lizards, many of which develop, either in the males or in both sexes, ornamental appendages, such as crests or pouches. As a rule, the tail is long and not brittle, but in only one genus is it prehensile, although in another it can be curled up at the extremity. The shape of the body is very variable in the different genera, the terrestrial forms being generally depressed, while those that are arboreal in their habits are compressed. Although the majority of the species are insectivorous, some subsist on leaves and fruits, while others prefer a mixed diet; but neither the nature of their habitat nor their food serve to classify the agamoids, many of the genera of which are very difficult to distinguish. The majority of the species appear to lay eggs, only the members of a single genus being reported to give birth to living young. As regards distribution, agamoids are found from the south of Europe to the Cape, and eastwards as far as China, the Malayan Islands, Australia, and Oceania, but are unknown in New Zealand and Madagascar. Both as regards genera and species, their headquarters is, however, the Oriental region ; Africa possessing only three genera, of which one is confined to the northern part of the continent, while but four species enter South-Eastern Europe. Commonly known as flying dragons, the members of the first Plying Lizards. ,, J & & genus of the family are elegant and harmless little creatures to whom such a title seems inappropriate, and we therefore prefer to substitute the name of flying lizards — more especially as we have applied the former appellation to the extinct pterodactyles. These flying lizards, which are represented by twenty-one species, ranging over the greater part of the Oriental region, are at once distinguished from all their kindred by the depressed body being provided with a large wing - like membranous expansion, supported by the elongated extremities of the six or seven hinder ribs, and capable of being folded up like a fan. The throat is furnished with a large membranous expansion, on the sides of which are a smaller pair ; and the tail is long and whip - like. The best known of the species is the Malay flying lizard {Draco volans), which is a rather common form, and belongs to a group characterised by the nostrils being lateral AGAMOID GROUP. 119 and directed outwards ; this particular species being distinguished by the absence of a spine above the eye, by the aperture of the ear being smaller than the eye, and by the inferior surface of the parachute being ornamented with black spots. In addition to the appendages on the throat, the males have a small crest on the nape of the neck ; while in both sexes the back is covered with irregular, large- keeled scales, and its sides have a series of still larger scales, which are also keeled. In length it measures a little over 8 inches. As regards coloration, the upper- parts are of a brilliant but variable metallic hue, ornamented with small dark spots and wavy cross bands ; between the eyes is a black spot, and a similar one occurs on the nape ; the parachute is orange, with marblings or irregular crossbands of black ; and the throat is mottled with black, its appendage being orange in the male and bluish in the female. This lizard inhabits the Malay Peninsula, Sumatra, Java, and Borneo ; and in the living state is described as being so superlatively beautiful as to baffle description. Essentially arboreal in their habits, the flying lizards generally frequent the crowns of trees, and as they are comparatively scarce, and seldom descend to the ground, they are but rarely seen. Describing the habits of the Malayan species, Cantor says that " as the lizard lies in shade along the trunk of a tree, its colours at a distance appear like a mixture of brown and grey, and render it scarcely distinguishable from the bark. There it remains with no signs of life, except the restless eyes, watching passing insects, which, suddenly expanding its wings, it seizes with a sometimes considerable, unerring leap. The lizard itself appears to possess no power of changing its colours." When excited, the appendages on the throat are expanded or erected ; and the ordinary movements of the creature take the form of a series of leaps. After commenting on the fact that both flying lizards and flying lemurs inhabit the same countries, and have very similar modes of life, Moseley states that, when springing from branch to branch and from tree to tree, the former pass so rapidly through the air that the expansion of the parachute almost escapes notice. Some examples kept on board ship were in the habit of flying from one leg of a table to another. The females appear to lay three or four oval whitish eggs. Oriental Among a number of genera, characterised by their more or less Tree-Lizards, compressed bodies and generally arboreal habits, the numerous tree- lizards constituting the genus Calotes may be selected for brief mention. These beautiful lizards belong to a group distinguished from many of their allies by the aperture of the ear being open, while they are especially characterised by the absence of any distinct fold of skin across the throat, by the equality in size of the large keeled scales on the back, and the presence of a large crest on the back and neck ; the tail being very long and whip-like. One of the best known species is the variable lizard (C. versicolor), ranging from Baluchistan, India, and Ceylon to the south of China, an exceedingly handsome lizard of some 16 inches in length, with a very large crest, but so variable in colour, when alive, as almost to defy description. It is one of the commonest of the eastern Asiatic lizards, and derives its name from its power of changing colour, which is especially marked when it is sitting basking in the sun ; the head and neck being often yellow, flecked with red, the body red, and the limbs and tail black. When irritated, or feeding rapidly, 120 LIZARDS. an allied species (C. ophiomachus), from India and Ceylon, turns brilliant red over the head and neck, the body at the same time becoming pale yellow ; hence it is popularly known as the " blood-sucker." Ceylon Homed Three remarkable lizards from Ceylon, constituting the genus Lizards. Ceratophora, and belonging to a group in which the aperture of the ear is concealed, derive their name from carrying a more or less elongated horn- like process on the nose, at least in the male sex ; the neck and back being devoid of a crest. One of the species, which attains a length of about 10 inches, has a horn measuring half an inch. These lizards appear to be very rare, one of the species being confined to mountain districts. For want of a distinct English title, we are compelled to designate True Agamas. x ° the members of the genus Agama collectively by anglicising their scientific name. Distinguished from all the previously noticed forms and their allies, with the exception of the flying lizards, by their more or less depressed bodies, agamas are especially characterised by the exposed aperture of the ear, and the presence of large callous scales in front of the vent in the males. The crest on the back is, at most, but small, and may be wanting ; while each side of the throat has a pit, and there is likewise a transverse fold across this part. A sac- like appendage may or may not occur beneath the throat, and the moderately long tail may be either cylindrical or slightly compressed. Less important characters are to be found in the form of the head, which is short and triangular, very broad behind, and rounded at the muzzle, as well as in the relative length and slenderness of the limbs. The head is covered above with small, smooth scales ; those on the back are overlapping and keeled ; while on the tail the scales may be either simply overlapping or arranged in whorls. The distribution of the genus is somewhat peculiar, impinging on South-Eastern Europe, and embracing the greater part of South-Eastern Asia, as well as the whole of Africa, but excluding India proper, together with Ceylon and Burma, although including the Punjab, Sind, and the Himalaya. As indicated by their depressed bodies, agamas are mainly ground-lizards, generally frequenting barren localities or rocks, although a few species resort to shrubs. The circular pupil of their eyes is equally indicative of diurnal habits ; and a large number of species are fond of basking on rocks in the full glare of the sun. In such situations, as in the valleys around Kashmir, they may be seen in numbers on almost every roadside mass of rock, where their extreme agility renders them very difficult to capture ; the best method, according to the writer's experience, when specimens are required for preservation, being to strike with the lash of a hunting-whip, whereby they are instantaneously stunned or killed. As regards food, all appear to be insectivorous.. From amongr rather more than forty representatives of the genus, Armed Agama. • three are selected for especial notice. The first of these is the armed agama (A. armata) of South Africa, which is represented in the figure opposite, and attains a total length of some 20 inches, of which rather more than 6 arc occupied by the tail. Belonging to the second great group of the genus, or that in which the occipital or hindmost median scale on the top of the head is enlarged, this species is characterised by the spinose scales on the back being of unequal size, by the aperture of the ear being larger than the eye, by the fifth toe being as long AG A MO ID GROUP. 121 as the first, and the third slightly longer than the fourth, as well as by the scales on the abdomen being keeled. Both sexes have a low crest on the nape of the neck, whereby the species is distinguished from most of its South African congeners ; while the males have two rows of twelve thickened horny scales in front of the vent. Although variable, this handsome lizard is strikingly coloured. Generally the upper-parts are olive-brown, with the enlarged scales lighter ; and there is a double series of darker blotches along the back ; the under surface being lighter, Spinose Agama. AHMED agama (f nat. size). and the throat marked with dark longitudinal streaks. Known to the natives of Mozambique by the name of toque, this species appears to feed chiefly on beetles, grasshoppers, and ants. Very different in general appearance to the last species is the spinose agama (A. colonorum) of West Africa, which is a rather large form, and said to be the most common reptile met with on the Gold Coast. It differs from the preceding species by the shields on the back being of uniform size and furnished with spines, as well as in the absence of a crest. The body is not much depressed, and the sides of the head near the ear, as well as of the neck, are ornamented with radiating groups of short spines, which are at least equal to two-thirds the diameter of the ear-opening. From an allied species (A. rueppelli) it may be distinguished by the scales on the back being very numerous, and considerably larger than those on the tail ; the latter being strongly keeled and arranged in fairly distinct rings. Attaining a length of rather more 122 LIZARDS. than 13 inches, this species is noticeable for its brilliant coloration in the living state, although the hues rapidly fade away after death. When alive, the head is flame-red, the throat spotted with yellow, and the body and limbs a deep steel-blue, While along the middle of the back there is generally a whitish line. The lower surface of the basal half of the tail is yellowish, the corresponding upper portion steely blue, as is the tip, while the remainder is red. Very old specimens have, however, both surfaces of the base of the tail blue, the remainder of the upper surface, except a small blue tip, being red. Females are at all ages, much more soberly coloured. In some spots these agamas are found in swarms, being very fond of climbing up the mud-walls and mat-roofs of the native huts, at times basking motionless in the sun, and at others running rapidly about in search of insects. When approached by a human being, they raise and depress their heads in a series of nods, which increase in rapidity as the intruder draws near, till, finally, the creatures lose courage, and disappear, with the speed of lightning, into some crack or cranny. So brilliant do these gorgeously-coloured lizards appear, when basking in the midday rays of an African sun, that the observer is fain to believe he is gazing on some splendid insect rather than a reptile. Rough-Tailed Belonging to a group of the genus distinguished from the one Agama. containing the species described above by the absence of enlargement of the occipital scale of the head, the rough-tailed agama (A. stellio), depicted in the illustration on p. 105, is interesting as being one of the two members of the genus whose range extends into South -Eastern Europe. Whereas, however, the other members of the group have the tail more or less ringed, the rough-tailed agama, together with the second European species (A. caucasica) and a third (A. microlepis), are peculiar in that the tail is divided into distinct segments, each composed of a pair of rings of scales. Growing to nearly a foot in length, the species under con- sideration is distinguished by its stout body and the moderate degree of depression of the head ; the cheeks of the male being somewhat swollen. The colour of the upper-parts is olive, spotted with black, and generally with a series of large yellow or olive spots down the middle of the back ; the throat of the male having fine bluish grey net-like markings. Occurring in Europe, in Turkey, and certain islands of the iEgean Sea, the rough-tailed lizard is distributed over the whole of Asia Minor, Syria, Northern Arabia, and Egypt, being much more common in the latter regions than it is in Europe. To the Arabs it is known by the name of kardun ; and it is commonly tamed and kept in captivity by the itinerant snake-charmers of Egypt. As shy and agile in its movements as its congeners, it feeds largely on flies and butterflies, which are captured with remarkable address and agility. Before taking leave of this extensive genus, it may be mentioned that there is a third group, agreeing with the last in the small size of the occipital scale of the head, but distinguished by the absence of rings on the tail ; the agile agama (A. agilis) of Persia being a well-known example. The genus Phrynocephalus of South-Eastern Europe and Central Asia comprises rather more than a dozen lizards nearly allied to Agania, but easily distinguished by the concealed aperture of the ear. Australian Although the swollen callous scales in front of the vent in the Frilled Lizard. males of the agamas have some resemblance to them, the whole of AGAMOID GROUP. 123 the preceding members of the family are characterised by the absence of true pores on this part of the body or on the thighs. In a second group such pores are, however, present in both, or in one or other of these situations ; and we select as our first example thereof the remarkable frilled lizard (Chlamydosaurus kingi) of Australia — the solitary representative of its genus. This extraordinary-looking creature, which attains a length of nearly 32 inches, about 11 of which are taken up by the tail, is at once recognised by the curious frill-like membranous expansion surrounding the throat and extending upwards to the sides of the nape. The frill, which is much more developed in the adult than in the young, has a serrated margin, and is covered with scales of larger size than those on the back ; it irresistibly reminds one of the frills with which our ancestors were wont to adorn their throats, and communicates an altogether strange appearance to its owner. In form, the body of this lizard is slightly compressed, and although the scales of the back are strongly keeled there is no distinct crest in this region. The aperture of the ear is exposed, and the tail is either round or slightly compressed, the latter condition occurring in the adult male. The general colour of the upper-parts is pale brown, which may be either uniform or mottled with dark brown, or blackish mingled with yellow. The frilled lizard is an inhabitant of Queensland and Northern and North- western Australia, as well as some of the islands of Torres Straits ; its fossil remains occurring in the superficial deposits of the first-named district. Recent observa- tions show that it inhabits sandy districts, where it walks, with a swinging gait, on its hind-legs, after the manner of the extinct iguanodon. When frightened, it sits down on its hind-quarters, raises its fore-quarters and head as high as possible, strikes its body with its tail, and shows its teeth at the intruder. Although the creature is perfectly harmless, this attitude has been known to frighten people who have seen it for the first time ; and it probably has the same effect on other enemies. The frill which, when fully extended, forms a shield concealing the body, limbs, and tail, is moved by certain special muscles, and is supported by rods of cartilage. Sail-Tailed Nearly allied to the preceding is the sail-tailed lizard (Lophurus Lizard. amboinensis), which is likewise the sole member of its genus, and takes its name from the presence of a tall sail-like crest on the upper surface of the tail of the adult, which is supported by a great lengthening of the spines of the vertebrae of that region. The body is markedly compressed, the back has a low crest, and the throat has both longitudinal puckerings and a transverse fold in the skin, while the aperture of the ear is exposed. In form, the head is short and thick, the compressed tail is long and powerful, and the legs and feet are also strong, the toes of the latter being covered inferiorly with small granular scales, and at the sides, especially externally, with a fringe of large united scales, which is one of the distinctive features of the genus. The covering of the upper-parts is in the form of small quadrangular scales, which are keeled on the head and back. The dentition comprises six small conical teeth in the front of the jaws, four long tusks, and thirteen cheek-teeth. On the thighs there is a row of pores. Attaining a length of over a yard, the sail-tailed lizard is of a general olive-brown colour, becoming greenish on the head and neck, and spotted and marbled with black ; while an oblique fold in the skin on the front of the shoulder is deep black. 124 LIZARDS. Originally brought to Europe from Amboyna, this curious lizard is an inhabitant of the Philippines, Java, Celebes, and the Moluccas ; it is arboreal in its habits, and is generally found in wood or scrub in the neighbourhood of water. Its food consists of seeds, leaves, flowers, and berries, as well as worms, myriapods, and other creatures found in damp situations. If frightened, this lizard immedi- ately dives into the water, and endeavours to conceal itself among the stones at /$&* a SAIL-TAILED LIZARD (J- nat. size). the bottom, where, however, it may be readily captured with a net, or even with the hand, as it makes not the slightest attempt at defence. Its eggs are laid in the sand of the river-banks. By the natives the creature is hunted for the sake of its flesh, which is white and well-flavoured, and consequently much appreciated. Thorny-Tailed Quite a different type of tail to that of the last is presented by Lizards. j-^q thorny-tailed lizards, of which there are seven species, inhabiting arid tracts in Northern Africa and South-Western Asia. From the whole of the foregoing members of the present family, these lizards are sharply distinguished AGAMOID GROUP. 125 by the circumstance that the front teeth, instead of being small and conical, are large, and in the adult united together into one or two broad cutting -teeth, separated from those of the cheek-series by a gap ; while externally they are easily recognised by their short tails covered with well-defined rings of spiny scales. The head is remarkably short and rounded ; the body, as in most terrestrial members ARABIAN THORNY-TAILED LIZARD [\ nat. size). of the family, is much depressed ; and there is no crest along the back. There are no folds or pouches on the neck, but pores are present both in front of the vent and on the thighs, and the aperture of the ear is exposed. The Arabian thorny- tail, or dabb, as it is termed by the Arabs ( Uromastix sjnnipes), is one of the best known members of the genus, and inhabits Egypt, Crete, and Arabia. It belongs to a group characterised by the rings of spiny scales on the upper surface of the tail being in juxtaposition; while, in common with two other species, it 126 LIZARDS. is specially distinguished by the circumstance that two or more transverse rows of scales on the lower surface of the tail correspond with one on its upper aspect. The Arabian species, which attains a length of about 18 inches, differs from its two nearest allies in the minute size of the scales covering the body, coupled with the presence of a few scattered somewhat larger tubercular scales on the flanks. Its colour is either sandy grey, or greenish above, which may be either uniform or clouded with brown. The ornate thorny-tail (IT. ornatus), of Egypt and Syria, differs from the other three members of the first group in that the scales of the tail form complete rings, those on the lower surface being as long as those on the upper. With the exception of one species (IT. microlepis) inhabiting Persia, the members of the first group are confined to Africa, Arabia, and Syria, whereas the three representatives of the second group are exclusively Asiatic, one (IT. loricatus) being from Persia, the second (IT. asmussi) common to Persia and Baluchistan, while the third (IT. hardwickei) is an inhabitant of Baluchistan and Northern India. In the whole of these three Asiatic species the rings of spiny scales on the upper surface of the tail are separated from one another by rows of smaller smooth scales. In the Indian thorny - tail the spines on the tail are small, with the lateral ones the largest; there are no enlarged tubercular scales on the back; and the front surface of the thigh is marked by a large black spot. In size this species is much inferior to its Arabian congener, not exceeding some 11 inches in length. Its colour is either uniform sandy above, or the same spotted or mottled with a darker, and whitish beneath, with the aforesaid dark mark on the thigh. Conforming in their sombre coloration to the desert regions they frequent, the thorny-tailed lizards are entirely vegetable-feeders, and live in burrows, resembling those of the smaller foxes, which are excavated by themselves. These burrows, which may be as much as 4 feet in length, sometimes, turn almost at right angles to their original course, at a depth of a foot or so from the surface. Generally living solitary or in pairs, these lizards are met with abundantly in parts of Eastern Persia and the Punjab, and when approached at once make for their holes. If they succeed in getting their fore-limbs within the aperture of their burrows, it is impossible to pull them out, for, as the writer knows by experience, they will rather suffer their tails to be pulled from their bodies than let go their hold. They are generally somewhat heavy and deliberate in the movements, turning their heads from side to side while walking, but are capable of running with tolerable speed. In the cold season, at anyrate, they never leave their burrows till the sun is well up ; and while in Persia and India they are commonly found on half-desert gravelly plains scattered over with low bush, the Arabian species is often met with in the clefts of rocks, whence it issues forth to bask on the smooth slabs or boulders. According to Brehm, as many as a dozen of these lizards may occasionally be seen on a single slab of rock. All the species appear to be timid and gentle in their disposition, rarely, if ever,, attempting to bite when captured. Their food comprises leaves and flowers, dried fruits, and the seeds of grass, as well as grass itself ; but although in the wild state they seem never to touch animal food, in captivity the Indian species will greedily devour meal-worms. According to Arab reports, the dabb never by any chance AG A MO ID GROUP. 127 drinks, even when water is at hand, and this statement has been confirmed by modern observers. By the Arabs these lizards are frequently tamed and kept in captivity; and their flesh, which resembles that of young chicken, is much relished by them as an article of food. Nothing appears to be known as to their breeding-habits. All the species thrive well in captivity in Europe. It is not improbable, according to Canon Tristram, that the reptile mentioned in Leviticus under the name of tortoise, is really the dabb. East African Two nearly allied lizards from East Africa — namely, Aporoscelis Thorny- Tailed princeps from Zanzibar and Somaliland, and A. batilliferus from Lizards. Somaliland, — while resembling the members of the preceding genus in general external characters, differ in the absence of true pores either on the under surface of the body or on the thighs, and are consequently referred to a distinct genus. Both appear to be rare, and are of comparatively small size, the first- named measuring only about 7£ inches in length. Even more strange and uncouth in appearance than the frilled lizard, is another Australian species commonly known as the moloch {Moloch horridus), but termed by the settlers the spiny lizard or thorny devil. This, the last remaining representative of the agamoids, differs from all the other members of the family in being covered with large conical spines, and in the con- formation of its mouth and teeth. In all the forms described above the mouth is large and the teeth of both jaws are erect, but in the moloch the mouth is very small, and the cheek-teeth of the upper jaw are placed horizontally, with their summits directed inwardly. About 8 inches in total length, this extraordinary lizard has a small head, with an extremely short snout, on the summit of which are pierced the nostrils ; it has a much depressed body, a short and rounded tail, and thick, powerful limbs armed with strong claws. On each side of the head immediately above the small eye is a large horn curving outwards and backwards, while there is a smaller conical spine above the nostril, a second behind the horn over the eye, a third and larger one in front of each ear, as well as one on each side of the occiput. Between these spines the upper surface of the head is protected by small granular tubercles ; while among the spines on the upper surface of the body, limbs, and tail, are similar granules intermingled with polygonal scales of which the edges are in apposition. On the back the spines form ten or more longitudinal series, of which the outermost are the largest. The lower surface of the body has a covering of rough, and slightly overlapping scales, among which are numerous rounded and keeled tubercles. In general colour the creature is yellowish, ornamented with symmetrical chestnut or reddish brown markings defined by darker borders. Inhabiting Southern and Western Australia, and being not uncommon in several localities in the neighbourhood of Port Augusta, the moloch is found only in districts where the soil is dry and sandy. Occasionally two or three may be observed basking in company on the top of a sandhill ; and it is the frequent habit of this lizard to bury itself in the sand to a small depth below the surface. Its small eye and general manner indicate pretty clearly that the moloch is diurnal in its habits, although it may possibly occasionally move about during the night. Although generally very slow in its movements, it has been known, when disturbed, to make for a neighbouring hole with considerable speed. In 128 LIZARDS. repose it generally rests with the head so raised as to be on the level of the back. Its chief food appears to be ants, although vegetable substances are sometimes eaten. The female deposits her eggs in the sand. To a certain degree the moloch is endued with the power of changing its colour to harmonise with its surround- ings, such changes taking place very gradually, although not unfrequently. The most general change is to a uniform sandy slate, or russet colour, when the ornamental markings almost completely disappear. In spite of its ferocious and somewhat forbidding appearance, the moloch is a perfectly harmless creature, its MOLOCH LIZARD (tiat. size). formidable-looking armour being never used for attack. In captivity it is dull and sluggish, undergoing fasts of a month's duration without any apparent incon- venience. The Iguanoid Lizards. Family IOUANID^E. The extensive family of lizards, of which the well-known iguanas of South America and the West Indies are the typical representatives, may be regarded as occupying the same position in America as is filled by the agamoids in the warmer parts of the Old World. Whereas, however, the agamoids are exclusively denizens of the Eastern Hemisphere, the iguanoid lizards are not absolutely confined to the PJSwl* THE BLACK IGUANA. IGUANOID GROUP. 129 western half of the globe, two genera occurring in Madagascar, and a third in the Fiji and Friendly Islands. Although, with these exceptions, the family is unknown in the Old World, the same perverseness which causes Anglo-Indians to speak of the Oriental crocodiles as alligators, leads to the monitors of the Old World being commonly termed iguanas, although few lizards are more unlike than the members of these two groups, both as regards external and internal characters. In their general structural features the iguanoids come very close to the agamoids. Thus in both groups the head is covered with numerous small shields ; while the back is clothed with scales of different kinds, which are often arranged in oblique rows. Similarly, the eyes have round pupils and are furnished with well-developed lids, and the drum of the ear is frequently exposed. Both groups, again, have two pairs of limbs, which may be relatively longer or shorter in the different genera, but are each provided with five toes. The length of the tail is subject to a large amount of variation, although it generally exceeds that of the head and body. Moreover, the two families resemble one another in the form and structure of the tongue, which is thick, short, scarcely notched, and generally fixed to the floor of the mouth throughout its length. When, however, we come to contrast the teeth of iguanoids with those of agamoids, we find a striking difference which at once serves to draw a sharp line of distinction between the two families. As we have already seen, in the latter group the teeth are attached to the very summits of the bones of the jaws (acrodont), and are commonly differentiated into front teeth, tusks, and cheek-teeth. In the iguanoids, on the other hand, the tall and cylindrical teeth are attached by their sides to the outer wall of the jaws in the so-called pleurodont manner; the whole series being generally more or less uniform in character, and without any large projecting tusks. In the typical iguanas the teeth have somewhat diamond-shaped compressed crowns with serrated edges ; and it was from a superficial resemblance to this type of tooth that the teeth of the great dinosaurian reptile from the English Wealden received the name of Iguanodon. A few genera, again, have the teeth divided into three lobes, thus resembling a fleur-de-lis. Many species of the family are further characterised by having teeth on the pterygoid bones of the palate, while a single genus is one of the few lizards in which there are teeth on the palatine bones. The iguanoids, which comprise about three hundred species, arranged in fifty genera, may be regarded as especially characteristic of South and Central America, although they extend into the warmer parts of the northern half of that continent, ranging in the west as far as British Columbia, and in the east to Arkansas and the Southern United States, while they are also represented in many of the American islands. Their occurrence in Madagascar (where, as in America, agamoids are wanting) has been already mentioned, and it is probable that this remarkable instance of discontinuous distribution may be explained by the occurrence of fossil remains of species of the family in the upper Eocene rocks of France, where agamoids seem likewise to have been wanting. Very variable in external appearance, iguanoids present equal diversity in their modes of life, and it is not a little curious that, with the exception of the flying lizard, almost every group of the agamoids finds a parallel, both as regards structure and habits, in the present family ; the two families being thus repre- vol. v. — 9 13° LIZARDS. sentative groups. There are, however, certain iguanoids, such as the anolis lizards and the sea-lizards which have no representatives in the preceding family. The majority of the iguanoids feed on insects, although some, like the true iguanas and the sea-lizards, subsist on a vegetable diet, while one genus is stated to be omnivorous. Only two genera are known to produce living young. In the forests, groves, and gardens of all the warmer regions of America live a number of beautiful lizards commonly known by the name of anolis, which is applied in the Antilles to some members of the group. The distinctive features of these lizards are the pyramidal form of the head, the moderately long neck, the presence of a broad and generally brilliantly -coloured appendage on the throat of the males, the slender body, which may be either com- Anolis Lizards. BED-THROATED ANOLIS (nat. size) pressed, cylindrical, or slightly depressed, the relatively long hind-limbs, the large feet, in which the toes are of very unequal length, and their middle joints expanded, with smooth transverse plates on the under surface, and the long, curved, and sharp claws, which are raised above the level of the expanded joints. The tail is long and hard, although not prehensile ; the covering of very minute scales on the back and tail is not unfrequently elevated to form a crest ; the cheek-teeth are characterised by their distinctly tricuspid crowns ; and teeth are generally present on the pterygoid bones of the palate. Lastly, these lizards possess the power of changing their colour to even a greater extent than is the case with the chamseleons. From among more than one hundred species belonging to the genus we select for illustration the red-throated anolis (Anolis carolinensis), which inhabits the South-Eastern United States and Cuba, and presents the following distinctive features. The head, which is long, triangular, and depressed, is nearly smooth in IGUANOID GROUP. 131 the young, but in the adult has well-marked frontal ridges, and some large rough shields on the crown ; and the appendage on the throat of the males is relatively- small. The body is not compressed, flat beneath, and not keeled above ; the scales on its upper and lower surfaces being keeled and approaching an hexagonal form, with their edges either in apposition or slightly overlapping. The tail is cylindrical and tapering, with some slightly enlarged scales on its upper surface, and nearly equal to twice the length of the head and body. In the living animal the colour of the upper surface is brilliant metallic green, and that of the under- parts silvery white ; the appendage on the throat of the males, which is covered with white scales, is red ; there is a large blue eye-like spot above the axil of the fore-limb ; and the region of the tail is ornamented with black markings. In some specimens the green colour passes more or less distinctly into brownish or brown ; and, when excited, the creature is able to change its general hue from greenish grey, through dark grey and brown of all shades, to the ordinary metallic green. In length this lizard varies from 5| to nearly 9 inches, according to sex ; fully two-thirds of these dimensions being taken up by the tail. In Louisiana, Carolina, and Cuba, the red-throated anolis is one of the most common of lizards, and may be noticed in all suitable spots, such as woods and garden-hedges, as well as the exteriors, and sometimes also the interiors of dwelling-houses. Like their congeners, they are, however, to be met with most abundantly in the deep woods, and then so closely do they assimilate to their surroundings that their presence, when at rest on a bough, is generally only revealed by their brilliant eyes. In houses, these lizards exhibit but little fear of man, running about with the greatest unconcern in search of flies and other insects ; and as, in addition to gnats, flies, butterflies, beetles, and spiders, they kill and eat wasps, scorpions, and other noxious creatures, their visits are encouraged. In motion throughout the day, they display extreme activity and speed, both when hunting among the foliage of trees or on the ground, pouncing upon their insect- prey like a cat upon a mouse. In the spring, during the breeding-season, the males display great jealousy of one another, so much so, indeed, that when two meet, a combat is certain to ensue, and is often continued till one of the combatants has lost its tail, which appears to be taken as an immediate sign of defeat. During these battles the appendage on the throat is inflated, and the changes of colour are more rapid than at any other time. With the advent of summer, these mutual animosities are, however, forgotten, and these lizards dwell together in perfect amity, sometimes collecting in large companies. The females of some of the species are stated to dig a hole for the reception of their few white eggs with their fore- paws, at the foot of a tree or in some moist spot near a wall, afterwards carefully covering them with soil to protect them from the sun's rays. The figured kind is, however, said to be very careless in regard to the place where its eggs are deposited ; these being found either on bare sand or rocks, or even in rooms. The red-throated anolis, like most of its kindred, can be readily tamed, and makes a most charming pet, which can be without much difficulty transported to Europe. Writing of a pair which were at one time in his possession, Bell says that " I was in the habit of feeding them with flies and other insects, and having one day placed in the cage with them a very large garden-spider, one of the lizards darted 132 LIZARDS. at it, but seized it only by the leg. The spider instantly ran round and round the creature's mouth, weaving a very thick web round both jaws, and then gave it a very severe bite in the lip, just as this species of spider usually does with any large insect it has taken. The lizard was greatly distressed, and I removed the spider and rubbed off the web, the confinement of which appeared to give it great annoyance ; but in a few days it died, though previously in as perfect health as its companion. The lizard was evidently unused to the wiles of the British spider." The crested anolis (A. cwvieri), belonging to a small group, with compressed and crested bodies and tails, is remarkable for the great extent to which the pouch on the throat can be inflated, — probably for the purpose of terrifying foes. Two lizards, respectively from Jamaica and Colombia, differ Allied Genera. ... from all the species of true anolis in having prehensile tails, in consequence of which they are referred to a distinct genus — Xiphocercus. In a third genus, Chamcelolis, the cheek-teeth have smooth and nearly spherical crowns. The strange form of the members of the present genus of Basilisks. , . ~ . .... iguanoids probably suggested to the earlier naturalists the imposition of the name basilisk, — a term which, as all our readers are doubtless aware, originally denoted a fabulous snake-like reptile before whose deadly glance every living being save the cock perished. Be this as it may, the reptiles now known as basilisks are large, although perfectly harmless members of the present family, belonging to a group distinguished from the preceding one by the absence of dilatation of the toes, and the more or less marked backward prolongation of the hinder portion of the head. In the presence of a large crest on the upper surface of the tail, the basilisks recall the sail-tailed lizards in the agamoid group, of which, indeed, they may be regarded as the representatives in the present family. As a genus, they are characterised by the head in the adult males being produced backwards into a large cartilaginous lobe ; by the compressed form of the body and tail, which are covered with small overlapping scales ; and by the presence of a crest on the back and tail in the males, such crests being always supported on the back by the prolonged spines of the vertebrae, and frequently also in the tail. Although there is a transverse fold on the throat, the pouch characterising the anolis lizards is wanting. The long limbs are covered with keeled scales ; and the outer sides of the hind-toes have a much developed lobe of skin. The cheek-teeth have three-cusped crowns ; and teeth are borne on the pterygoid bones. Internally, the basilisks form an exception to the members of this and the two preceding families in that the inner extremities of the collar-bones have a loop-like expan- sion, as in the geckos; while they differ from the anolis lizards in the absence of the false abdominal ribs so frequently present in this and the preceding families. The basilisks are represented by four species from Tropical America, among which the figured helmeted basilisk (Basiliscus americanus) is the one most commonly known. It is the largest representative of the genus, attaining a length of about 31 inches, of which nearly three-quarters is taken up hy the tail ; and is one of two species characterised by the great height of the crest of the tail in the males, which is supported by prolongations of the spines of the vertebrae. Inhabiting Panama and Costa Rica, it is specially characterised by the undivided head-crest of the males ; while the scales on the under surface of the body are I GUANO ID GROUP. *33 smooth. The natural colour of the creature is probably green, although specimens preserved in spirit are olive-brown above, and dirty white beneath. The back is marked with more or less distinct blackish transverse bands, while a lightish streak runs from the temple to the neck, and a more defined one from the region of the eye to the fore-limb. The banded basilisk (B. vittatus), ranging from Mexico and Ecuador, represents a second group of the genus, in which the tail-crest of the HELMETED BASILISK (£ liat. size). males is low, and not supported by bony rays. In this species the scales of the under surface of the body are keeled, whereas in the allied B. galeatus they are smooth. In general appearance all the basilisks suggest the idea of lizards upon whose backs has been grafted a fish's fin. As regards their habits, all the members of the genus spend their time either on trees, or bushes, often basking in the sun on fallen stems, and seldom, if ever, venturing far from the neighbourhood of water. Most numerous in the vicinity of rivers, basilisks are, indeed, so common in Guatemala, that the collector has no difficulty in obtaining as many specimens as i34 LIZARDS. he may desire, although the rapidity of their movements is so great that some practice is required to effect their capture. Their food is entirely of a vegetable nature; and to gather this the basilisks are astir with the first rays of dawn, while during the heat of the day they prefer to rest among the most leafy boughs. At the slightest sound, they raise the head, inflate the throat, and elevate the crest ; and as soon as the bright, yellow-irised eye detects the presence of a foe, the basilisks throw themselves instantaneously into the water above which they are usually reposing. In swimming, the head and neck are raised, the fore-limbs serve the part of propellers, while the crested tail acts as a rudder ; hence the common name of " ferrymen " is applied to these lizards. At the end of April or beginning of May the female lays from twelve to eighteen eggs in some cranny at the foot of a tree, where they are left for the sun to hatch. Ridge-Headed Nearly allied to the basilisks are the three species of ridge-headed Lizards. lizards (Corythophanes) of Central America, characterised by the head being prolonged backwards into a bony, helmet-like projection, while the tail is devoid of a crest, although the neck and back are provided with a low appendage of this nature. On the throat there is both a pouch and a transverse fold. The most interesting of the three species is the one named C. hernandezi, in which the head is crowned with a helmet-like prolongation so like that of the chamaeleon that the creature is commonly spoken of under that name by the Mexicans. Like the anolis lizards, these reptiles are in the constant habit of changing their somewhat sombre colours ; and it has been observed in a captive specimen that whereas the patch on the pouch was white during the day, at night it assumed, like the other light parts of the body, a blackish hue. While agreeing with the basilisks in having the plates on the under surface of the toes distinctly keeled, there are a number of genera in the family distinguished by the absence of any backward prolongation of the crown of the head. Among these we select for mention the stilted lizards, specially characterised by the large size of the occipital shield of the head, the presence of a vacuity in the breast-bone, the small or moderate-sized scales of the tail, the long and highly curved toes, and the presence of tusk-like teeth in the jaws. There are but two representatives of the genus, both of which have a wide distribution in South America. The figured species ( Uraniscodon umbra), which attains a length of about a foot, two-thirds of which are occupied by the long and cylindrical tail, has a short and frog-like head, raised into curved ridges over the eyes, with the muzzle very blunt, and the lower jaw longer than the upper. The skin of the neck is curiously puckered inferiorly, the folds forming a pair of pouches on the sides, although there is no pouch on the throat. In form, the body is at most but slightly compressed, with a low and slightly serrated crest running from the nape down to the back ; and the uniform scales of the back are small and overlapping, and those on the top of the head enlarged. The long and bent toes are markedly compressed, and are furnished with short but strong claws. In coloration this species is one of the handsomest of its tribe. The general ground-colour of the upper-parts is reddish or purplish brown, ornamented with more or less distinctly defined blackish transverse, bars ; a broad black band traverses the fold in front of the shoulder, and may extend across the nape ; while IGUANOID GROUP. 135 frequently in front of this band there is a large yellowish orange spot on each side of the neck. Below, the colour is brownish or yellowish, which may be either uniform or clouded with brown markings. An inhabitant of the great primeval forests of South America, the stilted lizard has the power of changing colour, and is consequently often designated a chamaeleon. It generally associates in pairs, dwelling among trees, and its food appears to be entirely of a vegetable nature. When disturbed, it rushes suddenly up a high branch, where it stands with outstretched head and neck and widely open eyes, gazing steadily at the intruder. Should it be unable to escape otherwise, the creature raises its neck still higher, inflates the neck-pouches, and, with a sharp cry, springs boldly into the air. There are a very large number of genera, agreeing with those hitherto noticed STILTED LIZARD (iiat. size). The Sea-Lizard. in the absence of pores on the thighs, which the limits of our space prevent us from even mentioning. We accordingly pass on to the consideration of certain repre- sentatives of the second great group of the family, in which such pores are present. Both as regards their fauna and flora, the Galapagos Islands stand altogether apart from the rest of the world, the greater number of their animals and plants being absolutely peculiar, — it may be specifically, or it may be generically, — while herbivorous reptiles take the place occupied on the continents of the world by vegetable-eating mammals. In no case, however, is this faunistic peculiarity more marked than in the occurrence in such a limited area of two distinct genera of the present family, each represented by a single species. Remarkable alike for special features connected with their dentition, as well as for their large bodily size, these two lizards differ widely from the rest of the family. Whereas, however, the one is a land animal, the other is unique 136 LIZARDS. among the entire suborder to which it belongs in being a marine creature, subsisting on seaweeds. Agreeing with the great majority of that section of the family characterised by the presence of pores on the thighs in the fourth hind-toe being longer than the third, the sea-lizard, together with the terrestrial species inhabiting the same islands, differs from all the rest in that the front teeth resemble those of the cheek-series in having three-cusped crowns, so that the entire set of teeth is uniform in character. From its terrestrial ally, the sea-lizard (Amblyrhynchus cristatus) is distinguished by its much compressed and crested tail, as well as by the presence of an incipient GALAPAGOS SEA-LIZARD (J nat. size). web between the toes. This lizard is the largest member of the family, and attains a total length of some 53 inches. It is characterised by the compressed form of the body and tail, and the extremely short and truncated head. A well-marked crest runs from the nape of the neck to the tip of the tail, and the whole build of the animal is stout and " chubby." The throat is devoid of a pouch, although it has a well-marked transverse fold, and the toes are laterally compressed. In the small and convex head the nostrils are situated near the end of the muzzle, the eye and aperture of the ear are alike small, and the upper surface is surmounted by a number of conical spine-like shields of relatively large size. The investing scales of the body are small, and although keeled on the back, are smooth below. In the stoutly-made limbs the toes are rather short, the third one in the hind-foot being IGUANOID GROUP. 137 strongly serrated on its inner border of its basal joint. The compressed and crested tail is about equal to one and a half times the length of the head and body, and is covered with equal-sized keeled scales. In colour this lizard is black or blackish brown above, with the abdomen and the inner surfaces of the thighs not unfrequently of a dirty white. In the "young state, however, the upper-parts are brown with paler spots, and more or less distinctly marked dark crossbars on the back. In weight, full-grown examples reach as much as 20 lbs. The sea-lizard is extremely common on the rocky coasts of the various islands of the Galapagos Group, but is seldom found more than some ten yards from the shore. Of its habits Darwin writes that " this lizard swims with perfect ease and quickness by a serpentine movement of its body and flattened tail — the legs being motionless and closely collapsed on its sides. A seaman on board sank one, with a heavy weight attached to it, thinking thus to kill it directly ; but when, an hour afterwards, he drew up the line, it was quite active. Their limbs and strong claws are admirably adapted for crawling over the rugged and fissured masses of lava, which everywhere form the coast. In such situations, a group of six or seven of these hideous reptiles may oftentimes be seen on the black rocks, a few feet above the surf, basking in the sun with outstretched legs." After mentioning that the stomachs of several examples that were examined contained finely minced seaweed, and also observing that the droves seen swimming out to sea were doubtless in search of food of this nature, the same author proceeds to state that, when frightened, these lizards absolutely refuse to enter the water. " Hence," he continues, " it is easy to drive these lizards down to any little point overhanging the sea, where they will sooner allow a person to catch hold of their tails than enter the water. They do not seem to have any notion of biting, but when much frightened they squirt a drop of fluid from each nostril. I threw one several times as far as I could into a deep pool left by the retiring tide, but it invariably returned in a direct line to the spot where I stood. It swam near the bottom, with a very graceful and rapid movement, and occasionally aided itself over the uneven ground with its feet. As soon as it arrived near the edge, but still being under water, it tried to conceal itself in the tufts of seaweed, or it entered some crevice. As soon as it thought the danger was past, it crawled out on the dry rocks, and shuffled away as quickly as it could. I several times caught the same lizard by driving it down to a point, and, though possessed of such perfect powers of diving and swimming, nothing would induce it to enter the water ; and as often as I threw it in, it returned in the manner above described. Perhaps this singular piece of apparent stupidity may be accounted for by the circumstance that this reptile has no enemy whatever on shore, whereas at sea it must often fall a prey to the numerous sharks." Later observers have borne testimony to the extraordinary numbers in which the sea-lizards are to be met with in the Galapagos, and likewise as to their food consisting mainly of broad- leaved sea-leaves. Galapagos Although originally included in the same genus as its aquatic Land-Lizards. COusin, there seems no doubt that the land-lizard of the Galapagos (Conolophus subcristatus) is entitled to stand as the representative of a distinct generic group ; the nearly cylindrical tail and perfectly free toes being distinctive characters which cannot well be overlooked. Not reaching within some 11 inches 138 LIZARDS. of the dimensions attained by the last, this lizard is likewise a stoutly - built creature, with the rather small head slightly longer than broad, the body some- what depressed, a slight spiny crest on the nape, continued as a low ridge on the back, and the scales of the latter small and keeled, while the slightly larger ones on the lower surface are smooth. Although devoid of a pouch, and with but a very slight transverse fold, the throat is strongly plicate longitudinally, and is covered with minute granules. The stout limbs terminate in very short toes, of which the third in the hind-foot is serrated on the inner margin GALAPAGOS LAND-LIZARD (£ nat. size). of its basal joint. On the thigh the pores are arranged in a long series, and vary from seventeen to twenty-one in number. In length the tail scarcely exceeds the head and body, while in form it is slightly compressed, having a low ridge superiorly, and being covered with small keeled scales of uniform size. In general colour the creature is dark brown, with the head and under-parts lighter. These lizards are confined to the central islands of the Galapagos Group, such as Albemarle and James Islands, where they are found in great numbers in the low barren districts near the coasts, although also met with in the elevated damp regions of the interior. On James Island Darwin found them so numerous, that it was difficult to obtain a spot free from their burrows on which to pitch a tent. Attaining a weight of from 10 to 15 lbs. these lizards are lazy and sluggish in their movements, crawling slowly along with their bellies and tails dragging on IGUANOID GROUP. 139 the ground, and often stopping for a minute or two to doze with closed eyes, and the hind-limbs stretched out on the arid soil. According to Darwin's account, " they inhabit burrows, which they sometimes make between fragments of lava, but more generally on level patches of the soft sandstone -like tufa. The holes do not appear to be very deep, and they enter the ground at a small angle ; so that when walking over these lizard- warrens, the soil is constantly giving way, much to the annoyance of the tired walker. This animal, when making its burrow, works alternately the opposite sides of its body. One front-leg for a short time scratches up the soil, and throws it towards the hind-foot, which is well placed so as to heave it beyond the mouth of the hole. That side of the body being tired, the other takes up the task, and so on alternately .... They feed by day, and do not wander far from their burrows ; if frightened, they rush to them with a most awkward gait. Except when running downhill, they cannot move very fast, apparently from the lateral position of their legs. They are not at all timorous ; when attentively watching anyone, they curl their tails, and, raising themselves on their front-legs, nod their heads vertically, with a quick movement, and try to look very fierce ; but in reality they are not so at all ; if one just stamps on the ground, down go their tails, and off they shuffle as quickly as they can." If worried with a stick, these lizards will bite it severely ; and when two are held together on the ground, they will fight and bite till blood flows. " The individuals, and they are the greater number, which inhabit the lower country, can scarcely taste a drop of water throughout the year; but they consume much of the succulent cactus, the branches of which are occasionally broken off by the wind. I several times threw a piece to two or three of them when together ; and it was amusing enough to see them trying to seize and carry it away in their mouths, like so many hungry dogs with a bone." They also eat the leaves of several trees, more especially of an acacia, to obtain which they ascend the low stunted trees, on the boughs of which they may often be observed quietly feeding. The females lay large eggs of an elongated form in their burrows ; both these and the flesh of the lizards themselves being eaten by the inhabitants of the Galapagos. The true iguanas, of which there are two closely-allied species True Iguanas. . . . from Tropical America and the West Indies, differ from the two pre- ceding genera in that the edges of the crowns of the cheek-teeth are serrated, while the front teeth are simply conical. The distinctive features of the iguanas are to be found in the long and much compressed body, the large four-sided head, covered above with enlarged scales, the short neck, powerful limbs, long-toed feet, and the much elongated tail, upon which the scales are uniform and keeled. The throat is furnished with a large non-dilatable appendage, in front of which is a crest of large compressed scales ; and a continuous crest of long spines runs from the nape along the back, and is continued as a ridge on the tail. The scales on the back are small, equal, and keeled; the neck has some scattered large conical or bluntly -keeled tubercles, and there are also some large tubercular scales on the sides of the throat, more especially one below the aperture of the ear ; while on the under-parts the scales are either smooth or slightly keeled. The pores on the thighs are numerous, and, in addition to those in the margins of the jaws, there are teeth on the pterygoid bones of the palate. The common iguana {Iguana tuberculata) attains a length i4o LIZARDS. of as much as a yard and a half, two-thirds of which are occupied by the tail. The general colour is green or greenish, becoming lighter on the under-parts ; but the upper surface may be either uniform, or variegated with darker brownish bands, the flanks usually having light-edged vertical dark bars, while the tail has more or less distinct dark rings. There is frequently a whitish band in front of the arm, and some of the large tubercular scales on the sides of the throat and neck are often light-coloured. Both species of iguanas, of which there are several varieties, are essentially arboreal lizards, generally frequenting those regions of the forests where the trees overhang the water. Here they move with great agility, climbing or springing from bough to bough, while the harmony of their coloration to their surroundings renders them well-nigh invisible. Towards evening they not unfrequently descend to the ground to feed; but, when frightened, immediately rush to the topmost boughs of the trees, or plunge headlong into deep water. In the latter element they are, indeed, perfectly at home, and swim strongly and swiftly, with their limbs closely applied to their bodies, and impelled by their powerful tails. They are likewise expert divers, frequently remaining for a considerable time below the surface ; their activity in the water being such that they are able to avoid all enemies save crocodiles and caimans. Their chief food consists of leaves, flowers and berries, although they will also eat insects; the numbers of small worms sometimes found in their stomachs having probably been swallowed accidentally. Generally seeking to escape at once from human beings, iguanas when unable to flee show fight, erecting their heads and assuming a fierce aspect, while at close quarters they bite savagely and administer severe blows with their powerful tails. The female deposits from eight to seventeen eggs in a hole dug in sandy soil, but as several individuals will not unfrequently lay together, as many as ten dozen eggs may be found in a single nest. In spite of their somewhat repulsive appear- ance, iguanas are hunted for the sake of their flesh, which is white in colour and delicate in flavour, and is said to resemble the breast of a chicken. The eggs also, which consist almost entirely of yolk, are highly esteemed as articles of diet. Iguanas are generally captured by means of nooses, which are thrown over their heads as they repose on the branches. The much smaller horned iguana (Meto- poceros cornutus), of San Domingo, constitutes a separate genus, distinguished by the presence of an inflatable pouch on the throat. Ring-Tailed The West-Indian ring-tailed iguana (Cyclura carinata) is selected iguana, ^o represent a group of genera distinguished from the foregoing by the crowns of the cheek-teeth being three-cusped or simply conical. While four of these genera — among which is the Fijian iguana (Brachylophus fasciatus) — are characterised by the shortness of the row of pores on the thigh, the present species is one of those in which they form a long series ; and it is further char- acterised by the presence of a serrated crest down the back and tail, and also of a pouch and slight transverse fold on the throat. The head is large, swollen below the ears, and furnished with enlarged scales on the snout ; while the body and tail are compressed, the body being covered with small scales. The species derives its name from the rings of keeled scales which form regular segments on the sides of the tail; each segment being composed of from three to five series of IGUANOID GROUP. 141 small scales, and a single series of larger and somewhat spinous ones. The toes are compressed, and covered below with keeled plates. In total length this iguana reaches about 48 inches ; and its general colour is green or dark olive, speckled with darker and lighter, and frequently marked with blackish transverse bands. The ring-tailed iguana is a somewhat local species, occurring most abundantly in Jamaica, on the limestone mountains in the neighbourhood of Kingston Harbour and Goat Island, but also met with on the low grounds lying between the coast ranges and the higher mountains of the interior, where hollow trees occur. Shy and retiring in their habits, the creatures live in pairs, and display no great partiality RING-TAILED IGUANA {\ nat. size). for water, although, on occasion, they can swim as well as the true iguanas. They feed mainly or entirely on grass, and when disturbed in grazing, these reptiles rush back to the trees with extraordinary speed, sometimes taking great leaps like a frog, although their movements are generally deliberate and slow. If unable to escape, they show fight in much the same way as the true iguanas. The breeding- habits of this species do not appear to be known, although the females of the allied black iguana (Ctenosaura acanthura) of California are in the habit of laying in company, like the true iguanas. The ring-tailed iguana exhales a peculiarly dis- agreeable smell, which is stated to be so objectionable as to cause even the ants to forsake a room into which one of these creatures is brought. For this reason its flesh is uneatable, although that of the black iguana is highly esteemed. 142 LIZARDS. Extinct Iguanas. We have not hitherto mentioned that the vertebrae of the iguanoid lizards differ from those of the agamoids and most other members of the suborder in being furnished with additional articular facets like those of snakes. Vertebras of this peculiar type occur in the upper Eocene rocks of England and the Continent, and have been provisionally assigned to the typical genus Iguana, although it is more likely that they indicate an extinct genus. Somewhat similar vertebras from the corresponding strata of the United States have been described under the name of Iguanavus. . The last and at the same time the most peculiar members of the present family are the horned lizards of North America and Mexico, which may be regarded as the representatives of the moloch lizard among the agamoids. From their short, rounded heads, abbreviated bodies, and shortened Homed Lizards. horned lizard (f nat. size tails, coupled with a general batrachian appearance, these lizards are commonly termed toads in America, the popular name of the figured species (Phrynosoma comutwm) being the Californian toad. Strange, not to say ugly, in appearance, these lizards are at once distinguished from all their allies by the presence of several bony spines projecting from the back of the shortened head, and of tubercles or spines scattered among the ordinary scales of the body. In form, the body is broad and depressed, without any crest down the back; and the tail is very thick at the base, and never longer than the body. The limbs are rather long, with pores on the thighs, and keeled plates on the lower surfaces of the toes. From most other members of the family these lizards are further distinguished by the absence of teeth on the palate. Of the twelve species of the genus the best known is the common horned toad, herewith figured, which has the tail longer than the head, distinct spines on the back, and the drum of the ear naked. Its general appearance is even more than superficially toad-like, the head being as GIRDLED LIZARDS. 143 broad as long, and the body remarkable for its extreme plumpness. Measuring a little over 5 inches in length, this species is rather handsomely coloured. Above, the ground-colour is greyish or brownish, with a more or less well-marked light stripe down the back, and dark brown spots at the bases of the larger spines ; while there are likewise markings of the same colour on the nape and head. Beneath, the hue is yellowish, with or without a few small brown spots. In two species of the genus (e.g. P. taurus) the tail does not exceed the head in length. The common species is found locally in sandy districts both on the plains and mountains, and is in some places abundant, although from its coloration frequently escaping notice. In spite of its somewhat formidable appearance, it is a harmless creature, not attempting to bite even when captured. Lacking the protrusive tongue of the chamseleon, and being debarred by its clumsy form from running fast, the horned lizard is unable to capture the swifter insects, and consequently preys upon sand-haunting beetles, whose speed is inferior to its own ; such prey being generally captured in the evening, and the creature lying passive on the sand during the day. Some species of horned lizards are remarkable as being the only members of the family, save one other genus, which produce living" young; the number of young being in some instances as many as twenty -four. Always small feeders, these lizards are capable of undergoing long fasts with impunity ; and as they are habituated to a dry atmosphere, and probably never drink, they may be sent packed in wadding long distances by post. The most remarkable peculiarity connected with these lizards is their habit of ejecting jets of blood from the eyes, apparently as a means of defence. The following letter from Mr. V. Bailey, written from California, in 1891, describes the phenomenon as first observed by him : " I caught a horned toad to-day that very much surprised Dr. Fisher and myself by squirting blood from its eyes. It was on smooth ground, and not in brush or weeds. I caught it with my hand, and just got my fingers on its tail as it ran. On taking it in my hand, a little jet of blood spurted from one eye, a distance of fifteen inches, and spattered on my shoulder. Turning it over to examine the eye, another stream spurted from the other eye. This he did four or five times from both eyes, until my hands, clothes, and gun were sprinkled over with fine drops of bright red blood. I put it in a bag, and carried it to camp, where, about four hours later, I showed it to Dr. Fisher, when it spurted three more streams from its eyes." The phenomenon has been subsequently observed in other specimens. The Girdled Lizards. Family ZoNURlD^E. Omitting mention of a family represented only by one genus (Xenosaurus) and one species from Mexico, the next group for consideration is that of the girdled lizards, from Tropical and South Africa, and Madagascar, of which there are four genera. These lizards, which may be either snake-like in form, or provided with four fully-developed limbs, differ from all those hitherto described, with the exception of certain geckos, in having the temporal fossae of the skull roofed over 144 LIZARDS. with bone ; while they are further characterised by a fold covered with small scales running along the sides of the body and marking off the upper from the under-parts. The tongue is simple, with its anterior moiety not extensile, and its tip either rounded, or but slightly notched ; while there are well-developed eyelids, and the drum of the ear is exposed. The back is either clothed with large shield- like, and mostly keeled scales, arranged in well-marked transverse zones, or, more rarely, with granules ; the head having large, regular shields. As regards their teeth, these lizards conform to the pleurodont type, each tooth having its base widely open. Resembling in many respects the Iguanoids, from which they are distinguished by the ossifications in the skull, these lizards also approach the members of the next family, from which they differ by their simple tongues, the CAPE GIRDLE-TAILED LIZARD (liat. Size. ) hollow bases of the teeth, and the structure of the bony plates underlying the scales, when such are present. In the South African snake-like genus (Chamce- saura), the fore-limbs are wanting, and the hind-pair rudimental, while the tail is of extraordinary length. All the members of the family appear to be carnivorous. Girdie-TaUed We take as our special example of this small family one of the Lizard. members of the South African girdle-tailed lizards (Zonurus), a genus represented by seven species. These lizards differ from the other three genera in having the scales of the back underlain by bony plates of simple structure ; and, resembling in appearance the rough-tailed lizard among the agamoids, they have a flattened triangular head, and a tail of moderate length. On the upper surface the neck and back are covered with large quad- rangular shield-like scales, while beneath there are large flat shields ; the limbs bearing keeled overlapping shields, and the tail being protected with whorls of SNAKE-LIKE LIZARDS. 145 spinous scales. The teeth are small, and the rounded tongue is scarcely notched. The figured species (Z. cordylus), which attains a length of rather less than 8 inches, generally has the back and tail of a dirty orange colour; the head and feet of a lighter yellow, and the under-parts white ; although there are consider- able variations from this normal coloration. All the members of the genus inhabit rocky districts, and prefer those where there are ledges, upon which they run in search of food or warmth. They are excellent climbers, and far from easy to catch, often leaving their tails with their would-be captors. The Snake-Like Lizards. Family ANGUID^E. Nearly allied to the preceding family is a small group of lizards of variable bodily form, typified by the common English blind- worm. Rigid in their bodies, and having large symmetrical bony shields on the top of their heads, these lizards resemble the girdle-lizards in the presence of bony plates beneath the overlapping scales, and also in that the temporal fossae of the skull are roofed over with bone. They differ, however, in that the bony plates beneath the scales are permeated by a series of radiating or irregularly arranged canals ; and also in the conformation of the tongue. The latter is composed of two distinct portions, namely, a thick basal half, covered with villose papillae, and a smaller thin terminal moiety coated with scale-like papillae, which is extensile, and capable of partial withdrawal into a sheath formed by a transverse fold at the front of the basal half. As regards their denti- tion, some forms have tubercular or conical teeth attached to the sides of the walls of the jaws in the typical pleurodont manner; but in the blind- worms the teeth are long, curved, loosely attached fangs, very like those of serpents. Instead of hollow- ing out the bases of the old teeth, as in the preceding family, the new ones grow up beneath them ; and there may or may not be teeth on the bones of the palate. Some of the members of the family agree with the preceding in having a longi- tudinal fold along the sides of the body, while in others it is absent ; and there is a similar variation in external form, some genera having fully developed five-toed limbs, while in others all external traces of these appendages have disappeared. In regard to the covering of the head, it should specially be noticed that there is a large occipital shield at its hinder extremity. All the species differ from the majority of lizards in changing their skin in a single piece, like most snakes. With the exception of some species of the American genus Gerrhonotus, which ascend low bushes, all these lizards live on the ground ; and the whole of them are carnivorous, the larger species preying on reptiles and other vertebrates, and the smaller kinds on insects, spiders, slugs, and worms. While the blind-worms produce living young, the others lay eggs. Containing seven genera and some forty-five species, this family is most numerously represented in Central America and the West Indies, a few species occurring in North and South America, two in Europe, and one in the Himalaya and Burma ; all the forms with functional limbs being American. From limitations of space, our notice of the family will be confined to two of the snake-like genera. vol. v. — 10 146 LIZARDS. Scheltopusiks. The typical representative of this genus of snake-like lizards (Ophisaurus apus) was first discovered by Pallas in the wooded valleys of the steppes bordering the Volga, where it is known, in common with true snakes, by the name of scheltopusik, a term which may be conveniently applied to all the members. The species was subsequently discovered in other parts of Russia, as well as in Hungary, Istria, Dalmatia, Greece, Asia Minor, Syria, Persia, Transcaucasia, Transylvania, and Turkestan, while it is replaced in Morocco by a more brilliantly coloured variety. Four other species are also known, which extend the range of the genus to North-Eastern India, Burma, and North America. Agreeing with the American four-limbed genus Gerrhonotus in the presence of a fold along the sides of the body, and the more or less conical teeth, the scheltopusiks are distinguished by their moderately elongated snake-like form, and the absence of functional limbs ; the European species alone having the hinder-pair represented by minute rudiments on the sides of the vent. These crea- tures are covered with squared scales, arranged in straight longitudinal and transverse series ; and they are furnished with teeth on the pterygoids, and in certain cases on some of the other bones of the palate. The European species, which, in addition to rudiments of hind- limbs, is distinguished by an aperture to the ear, attains a length of rather more than a yard, of which about two-thirds are occupied by the tail. The arrangement of the shields on the head is very much the same a#»in the blind- worm; and the general colour is brown, becoming lighter on the lower surface. The young are, however, olive- grey, with wavy dark brown crossbands on the back, and bars on the sides of the head. Dwelling among the dense underwood of thickly - wooded valleys, the scheltopusik harmonises so closely in colour with its surroundings, that it can only with difficulty be detected, as it glides away among the dead leaves and sticks at the approach of a footstep. Although as free from venom as ordinary lizards, it is frequently mistaken for a snake, and then meets the fate which so often, under similar circumstances, befalls the blind-worm. Preying largely upon mice and voles, and not even hesitating to attack and kill the deadly viper, the scheltopusik is, however, a fierce and active creature, gliding swiftly and suddenly upon its victims among the moss and leaves of the woods. It also subsists largely upon snails ; and is further reported to eat the eggs and young of birds. Its eggs are laid under thick bushes and leaves. The scheltopusik is believed to be a long-lived animal, the natives of the countries it inhabits stating that its full period of existence is from forty to sixty years. Fossil scheltopusiks occur in COMMON SCHELTOPUSIK. SNAKE-LIKE LIZARDS. 147 Blind-Worm. the Miocene deposits of Germany, some of which belong to an extinct genus {Propseudopus). The want of a lateral fold along the body distinguishes the blind-worm, or slow-worm (Anguis fragilis), in common with the remaining members of the family, from the scheltopusiks ; the blind- worm being further distinguished from the other genera devoid of this fold by the absence of all external trace of limbs, and the fang-like form of its cheek-teeth. The appearance of the blind- worm, which, by the way, is the sole representative of its genus* is so well known as not to call for much description. It may be observed, however, that the scales are rounded in form, and arranged on the back in a quincuncial pattern, while on the sides they are disposed in transverse rows ; the the blind-worm (§ nat. size). ears are usually covered with integument ; and the palate is toothless. Attaining a length of from 10 to 12, or even 14, inches, of which at least half is occupied by the tail, the blind-worm is of almost equal thickness throughout, although tapering slightly at the tail. The head is short and small; the eyes, although minute, are bright and piercing ; and the tongue is but slightly notched. In the immature state the upper-parts are silvery, with a dark line down the middle of the back, while the sides and under-parts are blackish. The markings, however, often disappear in the adult, or may be replaced by dark dots, the upper surface becoming at the same time brown or bronzy. The range of the species includes Europe, Western Asia, and Algeria. Gentle and inoffensive in its habits, and rarely attempting to bite even when rudely handled, the blind- worm is commonly regarded as one of the most noxious of reptiles. When captured, it usually contracts its muscles so forcibly as to 148 LIZARDS. become perfectly rigid, in which state it easily breaks if bent or struck, thus giving origin to its Latin name. Generally frequenting woods, heaths, and commons, the blind-worm is one of the hardiest of British reptiles, making its appearance in the spring at an earlier date than any other kind. According to Bell, " it retires in the autumn under masses of decayed wood or leaves, or into soft, dry soil, where it is covered with heath or brushwood, and penetrates to a considerable depth in such situations by means of its smooth, rounded muzzle and polished body." It feeds chiefly upon slugs, supplemented by various insects and worms. In June or July the female produces from seven to twelve or thirteen living young, which are active almost immediately after birth, and soon learn to feed by themselves. Like other viviparous reptiles, the female is much given to basking in the sun during the period of pregnancy, in order that its heat may aid in developing the eggs contained in her body. The Poisonous Lizards. Family Hewdermatid^E. Two conspicuously coloured lizards, ranging from the isthmus of Tehuantepec in Central America as far north as New Mexico and Arizona, stand alone in the sub- order in being poisonous, their bite, in certain cases at least, being sufficiently severe to produce very serious symptoms even on human beings, while smaller animals are soon killed thereby. These two species are the Mexican poisonous lizard {Heloderma horridum) of Western Mexico, and the Arizona poisonous lizard (H. swspectum) from New Mexico and Arizona ; the former being known in its native country by the name of silatica. Nearly allied to the blind -worm, which they resemble in the general structure of their tongue and teeth, although distinguished by certain peculiarities in the conformation of the skull, and by the upper surface being covered with small granular tubercles, externally they are characterised by the depressed head, the plump, rounded body, the tolerably long cylindrical tail, the rather short limbs, in which the third and fourth toes are longer than the others, the exposed drum of the ear, and the transverse arrangement of the rows of tubercles on the upper surface. The curved and fang-like teeth are but loosely attached to the jaws, and have grooves in front and behind for the transmission of the poison ; while there are also teeth on the palate. Beneath, the body and tail are covered with squared scales. In length, the figured species measures rather less than 20 inches, while the other is somewhat larger. The former has a yellowish or orange ground-colour, marked with a dark network on the head and body, and with blackish rings on the tail. Among the reddish sand, intermixed with dark pebbles, in which these lizards delight to nestle, this coloration, coupled with the granular nature of the skin, appears to be protective. Inhabiting dry regions from the western side of the Cordillera to the Pacific, and apparently never entering water, the poisonous lizards are nocturnal in their habits, lying during the day hidden among the vegetation in a listless state, and issuing forth at evening. Their movements are at all times deliberate; and as these lizards are most commonly met with in the wet season, being but seldom seen during the dry months from November to June, it is probable that they are MONITORS. 149 torpid during part of the latter period. Their food comprises insects, worms, myriapods, and small frogs, as well as the eggs of iguanas. Regarding the effects of their bite, Sir J. Fayrer writes that he once saw two guinea-pigs bitten by one of these lizards. " The bites were viciously inflicted, and the lizard did not really relinquish its hold. Blood was drawn, the teeth being deeply inserted. Both guinea-pigs were affected; the bitten limb was dragged, and appeared partially paralysed. There were twitchings of the body generally ; but these may not have been due to the poison, but to agitation and fear." Both the unfortunate rodents died in the course of the day. Another of these lizards once bit its Arizona poisonous lizard (£ nat. size). owner, who was incautiously handling it, with very severe effects, which did not, however, prove fatal. The poison is secreted in special glands situated near the roots of the teeth. The Monitors. Family Varanid^E. No better instance of the essential difference in the distribution of lizards as compared with tortoises is afforded than by those lizards commonly known as monitors. The tortoises of Australia, as we have already seen, belong to a different suborder from those of India, while there are no genera common to Australia and Africa. The monitors, all of which are included in the single genus Varanus, are, iSo LIZARDS. however, common to the three countries named, while one species actually ranges from India to Australia. . That this widespread generic distribution is not a feature of the present epoch is proved by the occurrence of fossil monitors in both the two latter countries; whereas we have no evidence that they possessed genera of tortoises in common. Before proceeding further, it is well to mention that the Egyptian representative of the group is known to the natives by the name of ouaran, which appears to be the Arabic term for lizards in general. Transliterated as waran, this word has been confused with the German warnen, to warn, whence these reptiles, have been termed wam-eidechsen, or warning lizards; this, again, having been translated into monitors — a name which, however erroneous in origin, is too well established to be superseded The monitors are distinguished from all the lizards hitherto described by the long and deeply-forked tongue, which is capable of being protruded far in front of the lips, and is furnished at the base with a sheath, into which it can be withdrawn, as in snakes. Including the largest members of the suborder, monitors are further characterised by the long body, the broad, uncrested back, the well-developed, five- toed limbs, and the long tail, which is very frequently markedly compressed. The head is covered with small polygonal scales ; the eyelids are well developed ; the opening of the ear is distinct ; and the head is covered with small scales. In the skull we may notice alike the absence of a bony roof over the temporal fossae, and of teeth on the palate ; while it is further remarkable for the union of the two nasal bones into a single ossification. The teeth are large and pointed, with ex- panded bases fixed to the sides of the jaws. On the back the scales are rounded and bordered by rings of minute granules, so that they do not overlap ; while in the under surface we find the squared scales arranged in cross rows. Pores are absent both on the under surface of the thigh and in front of the vent. A peculiarity of the group is the presence of an imperfect midriff, found elsewhere among reptiles alone in the crocodiles. Monitors inhabit Africa, Southern Asia, Oceania, Papua, and Australia, and are represented by nearly thirty living species, the largest of which attains a length a little short of 7 feet. A fossil species from Northern India was, however, probably 12 feet long, while one from Australia could not have fallen much, if at all, short of 30 feet. The group is an isolated one, without near relation- ship to any other family. The genus may be divided into four distinct sections, the first of which is represented solely by the desert-monitor ( V. griseus) of North- Western Africa and South- Western Asia, extending from Arabia and the Caspian to North- WTestern India. This species differs from all the rest in that the nostrils are in the form of oblique slits, while the tail, except sometimes near its tip, is cylindrical. Attaining a length of 4 feet 2 inches, and inhabiting the deserts of North- Western India, and thence westwards through Southern Asia to the Caspian and North Africa, it takes its name from its greyish yellow colour, which may be relieved by brown crossbars on the back and tail, and streaks of the same hue along the sides of the neck ; the young always having yellow spots and dark bars. In accordance with its sombre coloration, this species is an inhabitant of sandy deserts. A far handsomer lizard than the last is the Cape monitor ( V. albigularis) of Southern and South-Eastern Africa, where it is commonly known to the Boers as the " adder." It is the first MONITORS. 151 representative of the second group of the genus, in which, while the nostrils are in the form of oblique slits, the tail is compressed and keeled. Belonging to a sub- group characterised by the smooth scales of the abdomen, it is further distinguished by the absence of large (supraocular) scales above the eyes, by the nostril being three times as far from the snout as from the eye, and by the small size of the scales. It is slightly inferior in size to the last, and has the upper-parts greyish brown, banded and spotted with yellow, and the under-parts yellowish. It CAPE MONITOR {\ licit, size). generally frequents cliffs, or low rocky hills, in the interstices of which it delights to hide, coming out to bask on the flat surfaces. Gray's monitor (V. grayi) is an example of a second subgroup in which the abdominal scales are keeled. In the third great group, of which we take as our first example the water-monitor (V. salvator), represented in the coloured Plate, round or oval nostrils are accompanied by a compressed tail. In the species in question there is a series of transversely elongated scales above the eyes, the oval nostril is situated as far from the eye as from the tip of the snout, there are more than eighty transverse rows of scales be- 1 52 LIZARDS. tween the fold on the throat and the groin, and the scales on the nape are not larger than those of the back. This fine species, which ranges from India through the Malayan region and China to Australia, attains a length of nearly 7 feet, and is the largest of the genus. In colour it is dark brown or blackish above, with yellow rings ; the snout being generally lighter, with transverse black bars, and a dark band, bordered by a yellow one, running backwards from the eye ; the under surface being uniformly yellow. The water-monitor frequents marshy localities, being often found on trees overhanging rivers, and taking readily to the water, either fresh or salt. The last species that we notice is the well-known Nile monitor ( V. niloticws), whose range extends all over Africa except a portion of the north-western regions. Belonging to the same great group as the last, it represents a second subgroup distinguished by the equality in the size of the scales above the eyes ; while it is distinguished from its allies by the nostril being rather nearer the tip of the eye than the snout. In size it is somewhat larger than the desert monitor. The colour of the adult is brownish or greenish grey, with darker reticulate markings, and more or less distinct yellowish eye-like spots on the back and limbs; while beneath it is yellowish, crossed by some dark bands. This species is likewise found in the neighbourhood of water, generally building itself a nest among the bushes on the banks, especially of those streams that dry up in the hot season. The Papuan monitor ( V. prasinus) of New Guinea and the islands of Torres Straits, may be cited as an example of the fourth group of the genus, in which, while the nostrils are round, the tail is nearly or quite cylindrical. As will be gathered from the foregoing:, the monitors present Habits. . . & . & fc> r considerable diversity of habitat, although the majority prefer the neighbourhood of water. The Papuan species is, however, believed to be arboreal. All are carnivorous in their diet, feeding on frogs, snakes, the smaller mammals and birds, as well as the eggs of both birds and reptiles, especially crocodiles. Their movements are extremely rapid, both on land and in water ; and many a sportsman in his first day's snipe-shooting in the rice-fields around Calcutta has been startled by the sudden rush of the common Indian species ( V. bengalensis) as it darts among the herbage close to his feet. Those species in which the tail is the most compressed are the best swimmers; this appendage serving as a powerful propeller in the water, and being also used as a weapon of offence on land. In order to enable them to remain under water for some time, the nostrils are expanded into large cavities within the snout ; and when the apertures are closed these pouches serve as reservoirs of air. Writing of the great water- monitor, Cantor says that it is " very numerous in hilly and marshy localities of the Malayan Peninsula. It is commonly during the day observed in the branches of trees overhanging rivers, preying upon birds and their eggs and smaller lizards, and when disturbed it throws itself from a considerable height into the water. It will courageously defend itself with teeth and claws and by strokes of the tail. The lowest castes of Hindus capture these lizards commonly by digging them out of their burrows on the banks of rivers, for the sake of their flesh." Professor V. Ball gives the following account of a meeting with a lizard of the same species in the Nicobars : — " As I did not care to shoot him, though I wanted to capture him, I threw stones at him, whereupon he hissed and lashed his tail in a manner that GREAVED LIZARDS. 153 might prove alarming to anyone not knowing the harmless nature of the beast. As I was pressing him into a corner, he made a rush into the waves, but returned, apparently not liking the surf. Just as I thought he could not escape, he made a sudden dart into the water, dived through the surf, and disappeared." From observations made on specimens in captivity, it appears that these lizards eat eggs by taking them in their mouths, raising their heads, and then breaking the shells, so that the contents are allowed to run down their throats. Although but little is ascertained regarding their breeding-habits, monitors are known to lay white, soft-shelled eggs, which are deposited sometimes in the nests of white ants. As many as twenty-four eggs, of a couple of inches in length, have been taken from the bod}1" of a single female. By the Burmese these eggs are much relished as articles of food, and command a higher price in the market than hens' eggs. The Greaved Lizards. Family TeuBjE. In America the place of the true lizards of the Old World is taken by a nearly allied group which may be termed the greaved lizards, some of which rival the smaller monitors in size. In common with the remaining members of the suborder, these lizards are distinguished from all the foregoing by their tongues, which are slit at the tip and frequently shaped like an arrow-head, being either covered with overlapping scale-like papillae, or marked by oblique folds. In all, the head is covered with large symmetrical shields, very different from the small scales of the monitors. They further differ by the collar-bones being dilated, and often loop-shaped at their inner extremities. The greaved lizards are specially characterised by the absence of a bony roof to the temporal fossae of the skull, and by the shields of the head being completely free from the underlying bones ; while there are no bony plates on the body. On the body and tail the scales are arranged in transverse rows. The teeth, although very variable, differ from those of the true lizards of the Old World in not being hollow at the base ; the replacing teeth being developed in small sockets at the roots of those in use. In some cases these teeth, which may be either pointed or of a flattened crushing type, are placed near the summits of the jaws, and in others somewhat on the side, so that the dentition is intermediate between the typical acrodont and pleurodont modifications ; the front teeth are always conical. On the palate teeth are but seldom present, and, if developed, are small. The long tongue, which is frequently retractile within a sheath, is generally covered with overlapping scales ; the drum of the ear is exposed ; and the eyes are generally furnished with lids. The majority of the forms resemble the true lizards in, general appearance, although in some the number of toes is reduced to four. In others, however, the limbs take the form of mere stumps, while the hind pair may be wanting, in which case there is a near approach to the amphisbsenas. The greaved lizards comprise over a hundred species, arranged in thirty-five genera, which are distributed over the warmer parts of America, although most numerous in the equatorial regions. Various in their habitat, some frequent dry, J54 LIZARDS. sandy plains, others dwell among the herbage of meadows, while others prefer woods, and a few are partially or wholly subterranean ; these latter either taking possession of some empty hole, or digging one for themselves. In their general mode of life they resemble the monitors and true lizards, although some are. more like the amphisbsenas. They are generally swift and active in their movements ; and the larger kinds are thoroughly carnivorous, subsisting not only on insects, the teju {\ nat. size). worms, slugs, and snails, but likewise hunting such of the smaller vertebrates as they are able to overcome. Most species deposit their eggs in the hollow stems, or among the roots of trees. A few of the larger species are hunted for the sake of their flesh, which is stated to be tender and well-flavoured. One of the largest and best known representatives of the family is the lizard variously termed the teju, teguexin, or jacuaru (Twpinamhis teguexin), which ranges over a large portion of South America and the West Indies, and belongs to a genus comprising three species. These lizards GREAVED LIZARDS. 155 may be recognised by the tail being round at the root and slightly compressed near the middle, the double fold of skin on the neck, the uniform scales of the back, the rather small squared shields of the under surface of the body, which are arranged in more than twenty rows, the want of teeth on the palate, the com- pressed tricuspid cheek-teeth of the young, and the long tongue, which is of nearly equal width throughout, and sheathed at the base. In old individuals the crowns of the cheek-teeth become obtuse. The teju, which attains a length of about a yard, is a bulky and strikingly coloured lizard. Above, the ground-colour is olive, upon which are markings and bands of black, and more or less distinct rows of SURINAM AMEIVA {\ liat. size) lighter spots ; while the under surface is yellowish, with interrupted black bars ; the lines of division between the shields of the head being black. Ranging from Guiana to Uruguay, the teju is said by Bates to be very common in the forests of the Amazon, where it may be observed in numbers during the midday stillness scampering, apparently in sport, over the dead leaves ; while in other districts it haunts sugar-plantations. Although frequently found in the neighbourhood of water, it apparently never enters it; and generally dwells in wide-mouthed holes situated beneath the roots of trees. Shy and retiring to a degree in inhabited districts, when driven into a corner it shows fight, hissing at and striking with its muscular tail the dogs employed in its pursuit. When sitting, the head is generally raised, while the forked tongue is in constant motion. Its diet comprises such living creatures as it can capture, 156 LIZARDS. together with eggs. The female lays from fifty to sixty hard-shelled eggs about the size of those of a pigeon, generally placed in the hillocks of white ants. The dracaena (Braccena guianensis), of the Guianas and Amazonia, is a somewhat smaller lizard, distinguished by its compressed and doubly-keeled tail, the intermixture of keeled tubercles among the scales of the back, and the extremely broad crowns of the cheek-teeth. _ Our second figured representative of the family is the Surinam The Ameivas. . ... . ameiva (Ameiva surinamensis), belonging to a genus of nearly twenty species distributed over Central and South America, where they take the place occupied by the true lizards in the Old World. They are distinguished by their round, keelless tails, the presence of less than twenty rows of large smooth scales on the under surface of the body, and the compressed two- or three-cusped cheek-teeth. The tongue can be withdrawn into a sheath. The figured species, which is found over South America as far as Nicaragua, attains a length of from 15 to 20 inches, and is very variable in coloration. The young are olive-brown, with darker markings or white dots, and a black, white-edged band running along the side of the body and extending on to the tail ; these bands generally disappear- ing with age, although sometimes retained in the females. In the adult the upper surface is usually greenish, with some black and a few white spots ; while the under-parts are greenish white, spotted with black on the sides. Ameivas are generally found in dry districts — more especially near the coasts, and in their general habits are not very different from the teju, usually living in holes, among old wood, or the herbage of gardens. The Amphisb^enas. Family AMPHISBJENIDJE. Among the most remarkable of all lizards are those whose typical repre- sentatives have the power of moving equally well either backwards or forwards, from whence they derive the name by which the group is now commonly designated. Very nearly related to the preceding family, through those members of the latter with aborted limbs, the amphisbsenas are distinguished by the simple and degraded characters of the skull, in which all the arches have been lost, and the two premaxillary bones are fused into one. All are adapted to a purely subterranean existence, and have long, worm-like bodies, devoid, except in one species, of any external trace of limbs ; while even the bones of the shoulder and pelvis are more or less rudimental. The eyes are concealed beneath the skin ; the mouth is small, and frequently inferior in position ; and the ear is completely wanting. Although the head is covered with large symmetrical shields, the skin of the body is divided into squared segments forming regular rings, like those of worms; from which character the group is sometimes spoken of as the ringed lizards. In all the tail is short. The large teeth are few in number, and fixed either to the inner or upper edges of the jaws. The amphisbsenas, which are arranged in eleven genera, including between sixty and seventy species, are most numerously represented in America south of AMPHISB.-ENAS. 157 the Tropic of Cancer, although also occurring in the West Indies, while Africa possesses over twenty species, and four are found in the Mediterranean area. Of their habits, Mr. Boulenger observes that all the members of this family are burrowers, and may live in ants' nests. They bore narrow galleries in the earth, in which they are able to progress backwards as well as forwards. On the ground they progress in a straight line by slight vertical undulations, not by lateral movements, as in other limbless reptiles ; and the tail of many species appears to be more or less prehensile. The food of these lizards consists of small insects and worms. As regards their breeding- habits, it is only known that one species lays eggs, which are deposited in ants' nests. The marked resemblance of these lizards to earth-worms is a most curious instance of the similarity produced in the external HANDED AMPHISB.ENA (nat. size form of different groups of animals by adaptation to similar modes of life ; the remarkable feature in this case being the occurrence of this resemblance in creatures so widely sundered from one another, as are worms and amphisbsenas. Fossil members of the family have been discovered in the Tertiary rocks of North America. Handed The one member of the family which exhibits evidence of its Ampnisbaena. relationship to less specialised lizards in the retention of rudimentary fore - limbs is the handed amphisbsena (Chirotes caniculatus), of Mexico and California ; this being one of the two species found on the continent of America to the north of the Tropic of Cancer. This creature, which attains a length of about 7 inches, and is of a brownish flesh-colour, is distinguished by the presence of a pair of small depressed fore-limbs, placed close to the head, to which they are about equal in length ; each of these being provided with four well-developed and clawed toes, of which the outermost is the shortest. 158 LIZARDS. Typical The typical members of the family constitute a genus (Amphis- ' Amphisbsenas. hcena) common to Tropical America and Africa, and represented by nearly thirty species. Belonging, like the last genus, to the group in which the teeth are attached to the inner edges of the jaws, these limbless amphisbsenas are specially characterised by the anterior body-rings not being enlarged, by the laterally placed nostrils being pierced in a special nasal shield, by the rounded or slightly compressed snout, the obtuse, cylindrical tail, and the presence of pores in front of the vent. The figured species (A. fidiginosa) is a well-known kind from Tropical America and the West Indies, deriving its name from its pied, skin, and attaining a length of about 18 inches. Writing of the habits of a member of the genus, Bates observes that their " peculiar form, added to their habit of wriggling backwards as well as forwards, has given rise to the fable that they have two heads, one at each extremity. They are extremely sluggish in their motions, and live habitually in the subterranean chambers of the satiba ant ; only coming out spotted amphisb^na (§ nat. size). of their abodes occasionally in the night-time. The natives call the amphisbsena the mai das saiibas, or mother of the saiibas, and believe it to be poisonous, although it is perfectly harmless. It is one of the many curious animals which have become the subject of mythical stories with the natives. They say the ants treat it with great affection, and that if the snake be taken away from a nest the saiibas will forsake the spot. I once took one quite whole out of the body of a young jararaca [a poisonous snake], whose body was so distended with its contents that the skin was stretched out to a film over the contained amphisbsena. I was, unfortunately, not able to ascertain the exact relation which subsists between these curious reptiles and the satiba ants. I believe, however, that they feed upon the saiibas, for I once found the remains of ants in the stomach of one of them." The True Lizards. Family LACERTID^E. The true lizards, constituting the typical representatives of the suborder, form a large family, with seventeen genera, distributed over Europe, Asia, and Africa TRUE LIZARDS. 159 (exclusive of Madagascar), but most abundant in Africa, and comparatively rare in the Oriental countries. Taking the place in the Old World occupied in the New by the greaved lizards, these reptiles are readily distinguished from the latter by the temporal fossa of the skull being roofed over with bone (as shown in the figure of the skeleton on p. 108), and likewise by the shields of the head being firmly attached to the underlying bones, as well as by the union of the two premaxillary bones, the latter feature being common to this family and the amphisbsenas. All of them have well-developed limbs, each furnished with five toes, the body plump, and separated by a well-marked neck from the head, the tail long and brittle, the drum of the ear exposed, and the eyelids distinct and generally freely mobile. The skin contains no bony plates ; the scales of the back are either overlapping or in apposition ; while those of the under surface are generally larger, and arranged in longitudinal and transverse rows. The teeth are always attached to the sides of the edges of the jaws (pleurodont), and differ from those of the grooved lizards in their hollow bases ; those of the cheek-series having two- or three-cusped crowns. The flat and scaled tongue is of considerable length, and cleft both in front and behind, so as to assume the form of an arrow-head. As a rule, pores are present on the hinder surface of the thigh. Out of about one hundred species of true lizards, two are found in the British Islands, where, with the exception of the blind-worm, they are the only represent- atives of the suborder; but many others inhabit Southern Europe. Lizards of this family are veritably creatures of the sun, delighting to bask in its rays on some warm sandy bank, wall, or rock, and retiring to their holes and crannies in cloudy or rainy weather. The more powerful and bright is the sun, the more active, indeed, do these reptiles become, since most of them are dull and listless in the mornings and evenings, and only wake to full activity in the midday glare. Over the greater part of Europe they begin to spend a large portion of their time in their holes, and with the commencement of October retire for their winter sleep, from which they do not awake till spring is well advanced. Comparatively rare in Northern Europe, in the south of the continent lizards are common enough to form an attractive feature in the landscape, their burnished metallic green and bronzy scales flashing in the sunlight on every wall, and in every road and path. The darting movements of these pretty reptiles, as they are in pursuit of the flies and other small insects which constitute their chief prey, are familiar to all. While the majority lay eggs, the viviparous lizard produces living young. The pearly lizard {Lacerta ocellata) of Southern Europe, which is also represented by a variety in Algeria, may be taken as our first example of the typical genus Lacerta, of which there are over twenty species, inhabiting Europe, North and West Asia, Africa north of the Sahara, and the Atlantic islands. The members of this group, which may be collectively designated collared lizards, are distinguished by the following features. The body is cylindrical or slightly depressed ; the head pyramidal, with upright sides ; the neck not very well defined ; and the tail cylindrical, tapering, and long. The throat is furnished with a well-marked collar of enlarged scales ; the scales on the back are smaller than those on the tail, and are at most but slightly overlapping ; while the shields of the under surface are squared, and slightly overlapping. The rounded or com- 160 LIZARDS. pressed toes have either smooth, tuberculated, or indistinctly keeled pads on the lower surface, while the thighs have pores. In common with several other genera, the nostrils are placed close to the so-called labial scales, from which they are separated at most by a narrow rim ; and if there be a transparent disc in the lower eyelid, it is smaller than the eye. Among the most beautifully coloured members of the suborder the pearly lizard, which attains a length of from 16 to 23 inches, claims a foremost place. Belonging to a large group of the genus, in which the edge of the throat-collar is strongly serrated, this species agrees with certain other members of the genus in its smooth tail, and in the scales on the sides of the body not being smaller than those on the back. As special characters of the species, it may be noted that the scales are smaller than in the allied forms ; and that there are not less than seventy scales round the middle of the body, eight or ten of which belong to the under surface. The head is very large in the male, and characterised by the great width of its hindmost, or occipital, median shield. In colour, the upper-parts are either green, with black dots or network, or blackish olive with yellowish netting ; the sides are marked with a row of about a dozen eye-like blue spots; while the under surface is uniform greenish yellow. The olive-coloured young are, however, dotted all over with white, or pearly-blue, black-edged spots. Common in Spain, and also occurring in the south of France and North- Western Italy, or wherever the olive-tree grows, the pearly lizard is generally to be met with in the neighbourhood of hollow trees, frequently ascending some distance up their trunks, or even climbing among the branches. The males are somewhat quarrelsome, and the females lay from six to ten eggs, generally deposited in a hollow olive-tree. Another well - known European species is the green lizard Green Lizard. . . 7 . . _ , , . (L. viridis), attaining a length of about 12 inches in Germany, but in the more southern portions of its habitat measuring as much as 17 inches; fully two-thirds of this length being occupied by the long tail. Having not more than sixty-six scales round the middle of the body, this lizard is distinguished by the general presence of two small superimposed scales behind each nostril, the small size and triangular form of the occipital shield, and the arrangement of the abdominal scales in six longitudinal rows ; the collar being serrated. Usually the nostrils are in contact with the front or rostral shield of the head ; and in the female and young the foot is longer than the head. As regards colour, the males, which may be distinguished from the females by the larger and higher head, the thickened root of the tail, stouter hind-limbs, and generally superior size, are some shade of green-olive, passing below into yellow. Black dots, passing into large spots, generally adorn the upper surface, whereas the under-parts, save for a blue patch on the chin and throat, are uniform. The females, in which the blue on the throat is less constantly present, have a more brownish tinge, with the sides ornamented with black-bordered yellowish spots. The young are generally leather- brown in colour, with one or two yellow side-stripes. Both sexes vary, however, considerably according to age ; and southern specimens are more brilliantly coloured than those from the north. The green lizard is an inhabitant of the countries lying to the east and north of the Mediterranean, and thence extending eastwards to Persia. Very common in TRUE LIZARDS. 161 Portugal and Spain, where it is represented by a variety, it extends in France as far north as Paris, but it is unknown in Sardinia. In place of resorting, like the pearly lizard, to trees, this species is usually found on the ground, more especially in districts where the subsoil is rocky, ranging from the sea-level to a height of some three thousand feet, and being equally at home on the plains or among the mountains, in stony or sandy districts, on bare rocks, or among thick bush. As rapid as lightning in its movements, it feeds chiefly upon large insects and their larvae, together with slugs and worms ; living in grassy districts almost entirely upon grasshoppers, and at times attacking smaller species of its own tribe. In Switzer- land and Germany the female usually deposits her eight to eleven white eggs Sand-Lizard. GREEN LIZARDS (§ Hat. size). during June, these being hatched in the course of a month or so; and it is generally during the breeding-season that the blue on the throat is assumed by this sex. The third European representative of the genus is the much smaller sand-, or hedge-lizard (L. agilis), which is a more northern form, ranging into the British Islands and Scandinavia. Usually not more than 8 inches in length, although occasionally measuring nearly 10, this lizard may be recognised by its short, thick, and blunt-snouted head, and by the tail being considerably less than twice the length of the head and body. Never having more than fifty-eight scales round the middle of the body, it is further distinguished by the rostral shield of the head being separated by a small interval from the nostrils, vol. v. — n 162 LIZARDS. by the trapezoidal shape of the small occipital shield, by the absence of the row of small granules which occur between the shields of the eyelids (supraoculars) and eyebrows (supraciliaries) in the green and wall-lizards, and by the foot being not longer than the head. Although there is great variation in this respect, the general colour of the male is greenish, and that of the female grey or brown ; the crown of the head, a streak down the back, and the tail being mostly brown, while the chin and under-parts are greenish or yellowish. Tin streak down the back, and in the females also the sides, are marked by rows of white spots, which are sometimes large and eye-like ; and the under surface is marked with black. Some individuals, especially males, closely approach the green lizard in coloration. The range of the sand-lizard embraces North, Central, and Eastern Europe, and extends eastwards to Western Siberia and Asiatic Russia. In England it is generally found on sandy heaths, where it may often be seen running across the open paths with a speed less rapid than that of the more common viviparous species. It is more timid and less easily tamed than the green lizard, generally pining and refusing to feed in captivity. According to Bell, the female lays her eggs, to the number of twelve or fourteen, in hollows in the sand, which she excavates for the purpose, and having covered them carefully with sand, she leaves them to be hatched by the solar heat. Viviparous. A still smaller, and at the same time a more slightly built Lizar but m Hyperodapedon, there were numerous rows, as is shown in the illustration. The extremity of the beak in each jaw formed two curved tusk-like processes, which diverged in the lower one. The Permian rocks of Europe yield remains of genera, such as Proterosaurus and Palceohatteria, differing markedly from the fore- going, and constituting a second suborder (Proterosauria), characterised by the complex nature of the bones forming the shield on the lower surface of the body, by the fifth metatarsal bone of the hind-foot being of an ordinary type, and like- wise by the lower bones of the pelvis being expanded into large flattened plates, instead of comparatively narrow. The last feature allies the group to the earlier Sauropterygians. In the genus first named the vertebrae of the neck have cup- shaped articular surfaces behind and balls in front, and there are no intercentra between the vertebrae of the back, but in the other the articular surfaces of the Oldest Types. ANOMODONTS. *55 vertebrae are slightly cupped at each end throughout the series, and intercentra are present. The Anomodonts, or Mammal-Like Reptiles. Order Anomodontia. The last order of Reptiles, which is entirely extinct and confined to the Triassic and Permian epochs, is of especial interest to the evolutionist as being nearly allied to the ancestral stock from which Mammals have originated, and also equally closely related to certain extinct Amphibians noticed in the sequel, which were themselves evidently not far removed from the type whence sprang both Reptiles and Mammals. It should be observed, however, that these Anomodonts show the nearest relationship to the Egg-laying Mammals, and until we know the true affinity of the latter to the other members of the same class, it is of course impossible to at- tempt to define the genealogy more exactly. The Anomodonts are the only reptiles which agree with the \ Egg- laying Mammals in having three dis- tinct bones on each side of the true shoulder- girdle ; that is THE EIGHT SIDE OF THE PELVIS (A) AND SHOULDER-GIRDLE (B) OF AN ANOMODONT. il, haunch-bone, or ilium ; is, ischium ; pb, pubis ; of, foramen between ischium and pubis ; sc, blade-bone, or scapula ; p.cor, coracoid ; cor, metacoracoid ; gl, cavity for head of upper arm-bone, or humerus. to say, a blade-bone, or scapula, above, and a coracoid and metacoracoid below. Then the pelvis is very mammal-like, not only in that its three elements are united, but likewise in the small size of the vacuity, or foramen (of) between the pubis and ischium. It will also be seen from the two figures here given how close is the resemblance between the pelvis and shoulder-girdle of these reptiles, each having one bone above and two below. Even still more marked is the similarity between the upper arm-bone or humerus of the Anomodonts and that of the Egg-laying Mammals ; each having a perforation on the inner border of the lower end, whereas in those existing reptiles which possess such a perfora- tion (with the exception of the tuatera, where there is one on each side), it is situated on the outer border. As a rule, the Anomodonts further resemble Mammals in the absence of abdominal ribs ; and there are important similarities in the structure of the skull. 256 ANOMODONTS. Anomodonts are met with in the Triassic rocks, and are represented by at least four well-marked subordinal types. In the first group, known as Mammal - SKULL AND TEETH OP GALESAUB UPPER SURFACE OF THE SKULL OF A PAVEMENT- TOOTHED anomodont (J nat. size). toothed (Theriodont) Reptiles, the teeth, as exemplified in the figure of the skull of the African galesaur, are differentiated into incisors, tusks, and cheek-teeth ; the latter frequently having three cusps ranged in a longitudinal series. Whether, however, this marked mammalian type of dentition is indicative of genetic affinity with Mammals, may be open to doubt, as it is quite as likely to be due to parallelism in development. Another modification is presented by the Dicynodonts of England, Africa, and India, in which the jaws formed a horny beak, either destitute of teeth, as in the tortoises, or provided with a huge pair of tusks in the upper jaw; some of these reptiles being of gigantic size. A third group, known as Pavement-toothed, or Placodont Reptiles, which should probably be included in the order, are characterised by the presence of broad, flattened teeth on the palate and jaws, as shown in the figure on p. 5 ; the skull being very short and more or less triangular, with the double nostrils situated near the extremity of the muzzle, some distance in advance of the sockets of the eyes, which occupy a nearly central posi- tion. In all these forms, the skull has large temporal fossae in the hinder part of the upper surface ; but in the Wall-toothed or Pariasaurian Anomodonts, as shown in the cut, the hinder part of the skull was roofed over by bone, in the manner characterising the Labyrinthodont Amphibians, to which these reptiles were allied ; a peculiar sculpturing of the surface of the skull being another point of resem- blance. In the species, of which the skull is figured, a number of spines surmounted the head ; but these were wanting in the African pariasaur, which was a gigantic creature, with a somewhat frog-like head, an apology for a tail, and powerful short limbs, in which the toes were armed with long claws. UPPER SURFACE OF THE SKULL OF A WALL-TOOTHED anomodont (\ nat. size). FIRE-BELLIED FROGS (nat. size). AMPHIBIANS. CHAPTER I. General Characteristics, — Class Amphibia. Frogs and Toads, — Order Ecaudata. In popular estimation frogs and toads, together with their near relatives the newts and salamanders, are regarded as Reptiles, but they are really very different, and constitute a class by themselves, being in many respects intermediate between Reptiles and Fishes. From the mode of life of its members the very appropriate name of Amphibians has been proposed for the class, and is the one which should be adopted, although the term Batrachians, which more properly applies to frogs and toads alone, is not unfrequently used in the same sense. Agreeing with the higher Vertebrates in the structure of their limbs, which are divided into the same number of segments as in Mammals and Reptiles, and supported by corresponding bones, existing Amphibians are distinguished from Reptiles by the absence of any ossification in the basioccipital region of the lower surface of the hinder-part of the skull, in consequence of which the latter is articulated to the first vertebra by means of two condyles formed exclusively by the exoccipital bones. A further important point of distinction is afforded by the absence in the embryo of those membranous structures known as the amnion and allantois. Moreover, the great majority of Amphibians pass through a metamorphosis, or rather a series of VOL. V. — 17 258 AMPHIBIANS. metamorphoses, commencing their existence immediately after leaving the egg in a larval condition, during which they breathe the air contained in water by means of gills, while in the adult state they breathe atmospheric air by means of lungs. Varying much in external form, these animals nearly always have the body covered with a soft naked skin ; but in a few instances among existing forms scales are embedded in the skin, and most of the extinct forms had a well-developed armour of scales and bony scutes. In some forms a longitudinal fin is developed down the middle of the back and tail, but this is always soft, and lacks the support- ing spinous bones characterising that appendage in fishes. In passing through a metamorphosis, Amphibians are more like the inferior groups of animals than the higher Vertebrates ; and while in the earlier stages of their existence, during which they breathe by gills, they may be regarded as very closely allied to Fishes, in the adult state they come much nearer to Reptiles. The extinct Labyrinthodonts, which are themselves not very widely removed from fishes, and have the basi- occipital bone ossified, serve to connect other members of the class with the Anomodont and Beaked Reptiles. And it may be mentioned here that while in Mammals the skull has continued to be supported by the two condyles of the Amphibians, in the Reptiles the basioccipital bone has developed an intermediate condyle filling up the gap between the two exoccipital condyles, and thus forms a single tripartite condyle like that of the tortoises. Frequently, as in the crocodiles, the lateral elements have tended more or less completely to disappear, thus leaving a condyle formed almost entirely by the basioccipital. As already said, the skin of most existing Amphibians is soft and naked ; it is invested with a colourless epidermis, which is periodically shed entire, while the deeper layer is often coloured with blotches or streaks of yellow, red, brown, or black. Other colours, however, such as green and blue, are produced by pigment-cells, which generally make their appearance under special conditions of warmth and moisture. As a rule, the colour of Amphibians varies to a great extent with the nature of their surroundings, as is well exemplified in the case of the frog, which changes its hue according to the nature of its habitat ; while the tree-frogs harmonise with the foliage among which they dwell. It is, however, very remarkable that in Costa Rica a certain toad simulates to an extraordinary degree the coloration of the snakes — both poisonous and harmless — of the same country ; while in North Sumatra Amphibians of various groups are spotted with carmine-red. In all Amphibians the skin is furnished with glands secreting a more or less milk -like fluid ; these glands being generally distributed all over the body, although sometimes they are confined to the sides of the neck behind the eyes. In many toads and land-salamanders some of the larger glands appear as prominent warts, pierced with large pores. The viscid, milky fluid secreted by these glands is exuded during excitement, and is endued with more or less poisonous properties, being intended to serve as a means of defence. Although some degree of irritation of the skin may be produced by handling some of the species in which these poisonous properties are most developed, the stories of toads or salamanders spitting venom are, it is almost needless to observe, pure fabrications. When introduced into the circulati6n, batrachian venom acts, however, as a powerful poison, influencing the heart and central nervous system ; GENERAL CHARACTERISTICS. 259 and the secretion of a South American species is employed by the Indians to poison spears and arrows used in killing monkeys. BULL-FROGS DISPORTING. In the economy of Amphibians the naked skin and its glands play a most important part, since none of them drink, in the proper sense of the word, 26o AMPHIBIANS. but imbibe moisture through the pores of their integument. Moisture is, indeed, essential to their existence, and if they be confined in a dry atmosphere they soon perish. It is true that frogs may be seen basking in the sun's rays, and apparently enjoying the warmth as much as lizards, but they only do this in the neighbourhood of water, to which they retire when necessary. Such members of the class as inhabit dry localities, are mostly nocturnal, avoiding sunshine, and wandering abroad when they can obtain moisture from dew. The skeleton of the Amphibians presents many peculiarities, and Skeleton. . , , « , ,., , V. • • in some forms has numerous fish-like characters, ror instance, in certain of the forms with permanent gills the vertebrae are scarcely distinguishable from those of fishes ; whereas in the true newts they have a rounded knob at the front of the body and a cup at the hinder extremity, and are closely articulated with one another. In the long-tailed groups the number of vertebrae is consider- able ; but in the frogs and toads those of the back are reduced to seven or eight, SKELETON OF SALAMANDER. the hinder-end of the backbone terminating in a long style, extending between the greatly produced extremities of the haunch-bones, or ilia, which articulate with the lateral processes of the sacral vertebrae. The transverse processes of all the vertebrae are well-developed, and in some cases very long ; and they take the place of ribs, which, at the most, are represented by some small rudiments. In conse- quence of this absence of ribs, Amphibians are unable to breathe in the ordinary way by alternate expansion and contraction of the cavity of the chest ; and they, so to speak, swallow air, taking in a large gulp, and then closing the mouth. In addition to the peculiarities connected with its condyles and the basioccipital region, the skull is distinguished by its flattened, broad, and more or less semicircular form ; the sockets for the eyes being generally large and ill-defined. In front of the condyles the under surface of the middle of the skull is overlain by a large parasphenoid bone, which is frequently dagger-shaped ; this bone being generally but slightly, if at all, developed in the higher Vertebrates, although very large in Fishes. The lower jaw, which articulates with the skull by the interven- tion of a quadrate-bone, is composed of at least two pieces on each side, and may SKELETON. i6i SKELETON OF FROG. contain more elements. The palatines and vomer, and more rarely the parasphenoid, may be armed with teeth, like the upper jaw ; but in the frogs and toads the lower jaw is very generally toothless. In all cases the teeth are small, simple, and pointed ; being adapted for holding, and not for masticating. The shoulder-girdle, which is largely cartilaginous, is placed very close to the head, and com- prises the usual elements. Each scapula, or shoulder-blade, has an upper cartilaginous portion, ex- tending inwards nearly to the middle line of the back ; while in the frogs each metacoracoid has an inward cartilaginous expan- sion, which may either meet or overlap its fellow, and is of much importance in classification. In advance of the metacoracoid s is another pair of transverse bars commonly known as the precora- coids ; while in front of these is a single median rod termed the omosternum ; the proper sternum, or breast-bone, occupying a similar position behind the metacoracoids. In the fore-limb the radius and ulna may be united, and the wrist cartilaginous ; the number of toes among living forms never exceeding four, and being sometimes reduced to three. More variation exists in the hind-foot, the number of toes in the long-tailed forms ranging from two to four, whereas in the frogs and toads it is always five. Only in a few frogs and newts are the toes furnished with claw-like nails ; in the greater number of forms these being naked, although often connected by webs, and sometimes carrying adhesive discs on the lower surface. In all Amphibians the brain is of a very low type, its component portions lying in a line one behind the other, without overlapping. All possess the three chief organs of sense, although in some instances the eyes may be very minute and covered with an opaque skin. In frogs and toads the eye is large and very highly developed ; generally possessing two lids, of which the lower one is larger and thinner than the upper, and more or less transparent. Greater variation exists in the structure of the ear, which is simplest in the tailed forms. The nose opens externally in a pair of nostrils situated near the muzzle, and by another pair of apertures into the mouth ; the latter character distinguishing Amphibians from the majority of Fishes. The tongue, which acts only in the very slightest degree as an organ of taste, and is wanting in one group of frogs, is generally well-developed and thick, filling the whole space between the jaws, and being capable of a large amount of motion ; it differs essentially from that of the higher Vertebrates in that it is affixed to the inner side of the front of the lower jaw, with its tip pointing down the throat. All Amphibians lay eggs, which are generally although not invariably deposited in fresh water, and fertilised as they are Soft Parts. Development. :62 AMPHIBIANS. extruded from the female. As a rule, these eggs, which much resemble those of fish, are small, very numerous, and connected together by mucilage, forming either a string or a jelly-like mass in which the dark yolks are very conspicuous. Some of the tree-frogs, however, lay large eggs, within which the larvae undergo the whole of such transformation as takes place; and in one genus, instead of the usual gills, a temporary breathing-organ is developed on the tail. A land-frog in the Solomon Islands also lays large eggs, like small marbles, which are deposited in the crevices of rocks, and from which emerge fully-developed frogs. The eggs, with certain exceptions, are deposited in water, where they are hatched by the heat of the sun ; and it appears that the dark colour of the yolk is for the purpose of absorbing as much solar heat as possible. Such eggs as are laid during the late spring and summer are less darkly coloured, and have thinner coats, than those deposited in the early part of the spring ; and while the DEVELOPMENT OF THE FllOO. 1, Eggs when first laid ; 2, Eggs at a later stage ; 3, Egg containing embryo ; 4, Newly-hatched larva? ; 5, 6, Larvae with external gills ; 7-12, Later stages in the development of larvae. former are placed on the ground at the bottom of the water, the latter float on the surface; the reason of this difference being that in the early part of the year the lower strata of water are too cold to admit of the development of the ova. In ordinary cases, when the larva has reached a certain stage, it bursts the investing membranes of the egg, and comes into the world adapted for an aquatic life, and always possessing a long compressed tail composed of zigzag- shaped masses of muscles, similar to those of fishes. The first process is the sprouting forth of branching external gills from the sides of the neck, which in the larvae of the frogs and toads are subsequently replaced by internal gills, but in the long-tailed forms persist for a longer period. After the disappearance of the external gills, the water is expelled from the gill-chamber by one or two tubes, generally discharging by a single orifice, which may be situated either on the lower surface of the body, or on the left side. As soon ' as the external gills have made their appearance, development is concentrated on the tail and the absorption DISTRIBUTION. 263 of the remainder of the yolk. The vertical fin-like expansions of the tail rapidly increase, and the body becomes relatively smaller and more slender; while the limbs begin to make their appearance as buds, although the date of development of the front and hind-pair varies in different groups. In the newts, the front pair of limbs are the first to appear, in the frogs the reverse is the case. In the latter the hind-limbs appear some considerable time before the front pair, the fish-like tail persisting till the sprouting of these, when the change from a herbivorous fish-like animal to one carnivorous and reptiliform begins. The jaws are at first invested with horny teeth, and subsequently with horny sheaths, which eventually disappear ; while the tail gradually diminishes in size, and finally is lost. It may be observed that no vertebrae are developed in the frog's tail ; and that the long spine in which the backbone of the adult terminates is an outgrowth from the hindmost vertebra. Not less remarkable is the shortening of the intestinal canal, as the creature changes its herbivorous for carnivorous habits. To trace in detail the development of the soft parts would greatly exceed our limits of space. We may mention, however, that in one group of Tailed Amphibians the external gills of some individuals may be retained permanently, while in others of the same species they are cast at an early period. Then, again, the number of these gills is by no means constant, for in the Cingalese csecilian and the salamander there are three pairs of these organs, in the tadpoles of some frogs there are two, and in others, as well as in one genus of csecilians, there are only a single pair. Geologically the Amphibians are a very ancient group, their Distribution. te J c . _ . J ,„ . oldest representatives occurring in the Carboniferous and Permian rocks of Europe and North America. All these ancient representatives of the class belong, however, to the group of Labyrinthodonts, which survived till the period of the Trias, and are structurally very different from the modern forms, approximating in certain respects to fishes. Indeed, since no Amphibians have hitherto been discovered between the Trias and the Wealden, or lower Cretaceous, rocks of Belgium, we are quite unable to assert that the modern representatives of the class are the direct descendants of the Labyrinthodonts. Commencing in the Belgian Wealden, the newts and salamanders occur throughout the greater part of the Tertiary rocks ; but the frogs and toads are first known in North America from Eocene beds, while in Europe they are not met with before the Oligocene. At the present time Amphibians are distributed over all parts of the world except the polar regions ; although they are more dependent upon the presence of water and warmth than any of the preceding classes of Vertebrates. They are, accordingly, most abundant in the tropical and subtropical regions ; and as none of them are marine in their habits, even a narrow arm of the sea is generally sufficient to limit their habitat. When they occur on islands, it is probable either that their eggs have been carried by birds, or that there has been a comparatively recent separation from the mainland. In absolutely desert districts Amphibians are unknown ; while in countries where there is a long dry season, followed by a period of rains, they are in the habit of becoming torpid during the former ; the length of the sleep in one Javan species being upwards of five months. In cold climates all the members of the class become torpid during the winter. 264 AMPHIBIANS, As regards their general distribution, Amphibians closely resemble fresh-water fish, and differ widely from lizards. Indeed, from an Amphibian point of view, the globe may be divided into two great regions, namely, a northern one characterised by the abundance of newts and salamanders, and the absence of caecilians ; and a southern one distinguished by the want of the former and the presence of the latter group. In their mode of life, it is probable that very few Amphibians are diurnal ; most of the terrestrial forms making their appearance abroad with the first shades of evening, and retiring to their hiding-places at dawn. In wet or cloudy weather frogs and toads — especially in South America — frequently appear in great numbers during the day ; and both these groups are Habits. moor-frogs (nat. size). in the habit of making night hideous with their croakings. Although in all cases the adults are carnivorous, the larvae subsist more or less exclusively on vegetable substances; some confining themselves to that kind of diet, while others also consume animalcules and other minute creatures. Characteristics of The f rogs and toads are distinguished from their allies by the Frogs and Toads, presence of four limbs and the absence of a tail in the adult state ; the latter feature giving origin to the name Ecaudata, by which the order to which they belong is scientifically designated. They all have short and frequently thick bodies, in which the backbone comprises, at most, only eight vertebrae in advance of the sacrum ; those behind the latter being fused into a long rod-like bone, as shown in the figure of the skeleton on p. 261. In the fore-limb, as shown in the same figure, the bones of the fore-arm (radius and ulna) are completely fused together ; and the same is the case with regard to the tibia and fibula in the hind- TYPICAL FROGS. 265 leg. Moreover, the hind-limb obtains a kind of additional segment, owing to the elongation of the calcaneum and astragalus in the ankle-joint, which form a pair of long bones lying parallel to one another. As a rule, frogs and toads undergo a lengthened larval period ; the " tadpoles," as shown in the figure on p. 262, having a globular head and body, a fish-like tail, external or internal gills, and no limbs in the first stages of their existence. The hind-limbs are the first to appear, and after the front pair are developed the tail is gradually absorbed, upon which the young for the first time leave the water. Represented by about a thousand species, frogs and toads have a worldwide distribution, although more abundant in tropical and subtropical than in temperate regions, and being especially numerous in India and South America ; and it is not a little remarkable that some of the largest forms are inhabitants of islands. From the nocturnal habits of the adults it is frequently difficult to find out whether in any locality these reptiles are abundant or the reverse ; but in the spring this may generally be ascertained by observing the tadpoles in the rivers and points, since all of these show specific differences, to the full as well marked as those in the adult. The Typical Frogs. Family Ranid^:. The typical frogs, together with four other families, constitute a suborder (Firmisternia), characterised by the presence of a tongue, and by the firm union of the two metacoracoid bones of the chest by means of a single cartilage uniting their free edges. From the other members of the group, the typical frogs are distinguished as a family by the presence of teeth in the upper jaw, and by the transverse processes of the sacral vertebra being either cylindrical, or but very slightly dilated at their extremities. These characters are sufficient to distinguish the typical frogs from the other families of the suborder ; but it may he added that the vertebrae are cupped in front and hollowed behind ; while there are no ribs ; and the terminal style of the backbone is articulated to the sacrum by two condyles. The terminal joints of the toes may be either simple or pointed, T-shaped, Y-shaped, or even claw-like ; the species in which these joints are thus. expanded having the soft parts similarly expanded and flattened. For a long time it was considered that the shape of the tips of the toes was connected with the mode of life of their owners ; and although this is so to a great extent, it is now ascertained that several of the species in which the toes are somewhat expanded are as aquatic as those in which they are pointed, and species presenting both modifications are included within one and the same genus. The typical frogs are divided into twenty genera, only two of which are noticed in this work. Under the general title of water-frogs may be conveniently Water-Frogs. . ° . included all the members (some hundred and forty in number), of the genus Rana, to which belongs the common English frog. The distinctive characters of these frogs are to be found in the horizontal pupil of the eye; the more or less deeply notched and free tongue ; the presence of teeth on the vomerine bones of the palate ; the absence of webs in the toes of the fore-feet, and their presence 266 FROGS AND TOADS. in those of the hind-limb ; and the separation of the outer metatarsal bones of the hind-foot by a web, the extremities of the fingers being simple or expanded. With the exception of the southern part of South America (where the whole family is unrepresented), Australia, and New Zealand, these frogs have a worldwide distribution. Although the greater majority of the species are probably aquatic during the breeding-season, at other times great diversity of habit is displayed by the different representatives of the genus, some being aquatic, others terrestrial, and others, again, burrowing, or even more or less arboreal. The existence of burrowing habits is indicated by the great development of a tubercle on the inner side of the metatarsus, which in one Indian species (Rana breviceps) has a sharp edge, and is used in a shovel-like manner to excavate the burrow. Such burrow- ing species are further characterised by the shortness of the hind-limbs, and thus assume a more or less toad-like appearance. Large discs at the ends of the toes usually, on the other hand, are indicative of arboreal habits ; although, as already said, smaller discs are met with in certain purely aquatic species. Selecting some of the European representatives of the genus for European Frogs. . . . . special mention, we may first notice the edible frog (R. esculenta), characterised by the pointed tips of the toes, the smooth under surface of the body, the presence of a broad glandular fold along the sides, and the marbling of the thighs. Exceedingly variable in coloration, this frog generally has the upper-parts olive or bronzy brown, more or less spotted or marbled with dark brown or black ; there are generally three light stripes along the back, while the sides of the head and ground-colour of the flanks are sometimes green ; the marbling on the thighs occupying their hinder surfaces, and being black in colour. The males are specially characterised by the presence of a globular sac, connected with the production of the croaking, on each side of the head, opening by a slit behind the angle of the mouth. Inhabiting Europe, Asia as far west as Japan, and North- Western Africa, the edible frog is common in England, the dark race occurring in the fens of Cambridgeshire, and the green variety in Norfolk. The use of the flesh as food probably led to the introduction of this species into Cambridgeshire by the monks ; while the Norfolk colony was imported between 1837 and 1842. From this species the common English frog (R. temporia) is readily distinguished by the incomplete webbing of the hind-feet, and the presence of a dark temporal spot extending from the eye to the shoulder, as well as by the absence of external vocal sacs in the males. Moreover, if the skulls of these two species be compared, it will be found that while in the edible frog the teeth on the vomers do not extend behind the line of the apertures of the posterior nostrils, they do so to a small extent in the present species. In colour the upper-parts of the common frog are greyish or yellowish brown, more or less spotted with dark brown or black ; the temporal spot being always dark, and a light line running from below the eye to its extremity ; while the sides of the body are profusely spotted, the limbs trans- versely barred, and a larger or smaller number of spots are present on the under- pays. This species is spread over Europe and Northern and Temperate Asia. Closely allied is the moor-frog (R. arvalis), of Eastern Europe and Western Asia, represented in the illustration on p. 264, which may be distinguished by the tubercle on the inner metatarsal being compressed instead of blunt, and by the TYPICAL FROGS. 267 pointed, in place of obtuse, muzzle. The coloration is very similar to that of the common species, but there is sometimes (as in the right-hand figure of the illustra- tion), a light stripe bordered by two black ones down the middle of the back, while the under-parts are uniform. A third European species is the agile frog (R. agilis), which belongs to a group distinguished by the greater length of the hind- limbs ; the whole form being slender, and the muzzle pointed. Its general colour is greyish brown, with dark spots ; the temporal spot being dark and distinct, with a light line running from its extremity to the snout, while the hind-limbs are regularly barred, and the under-parts unspotted. Two other European species, the cm* agile frogs (nat. size). one (R. iberica) from Spain and Portugal, and the other (R. latastei) from the neighbourhood of Milan, differ by the spotted lower surface of the body. Even the tadpoles of the whole of these more or less nearly allied species present differences by which they can be distinguished from one another. The common frog, whose habits may be taken as typical of the allied members of the genus, is found in most parts of Europe, where there is a sufficiency of moisture and shelter for its existence ; the presence of water being essential during the breeding-season. All are probably familiar with the manner in which a frog swallows air ; but it is perhaps less generally known that if the mouth of one of these creatures be kept forcibly open, death must inevitably ensue, owing to the impossibility of breathing while in this state. The croaking of the frog is principally uttered during the breeding-season ; and when large numbers of these 268 FROGS AND TOADS. Amphibians are collected in a pond together, the volume of sound produced is con- siderable, and can be heard from long distances, although it is nothing compared to that of the bull-frog and many tropical species. Frogs subsist entirely on slugs, snails, insects, etc., swallowing large beetles whole, and devouring several at a meal. The frog captures its prey by suddenly throwing forwards the tip of its tongue, which is invested with a viscid secretion, upon the insect or slug, and then as quickly withdrawing it to its normal inverted position. So rapid is the whole movement, that it requires a sharp eye to detect it ; the insect seeming to disappear as if by magic. " Frogs retire," writes Bell, " on the approach of winter to their hibernating retreats, where they pass the dreary season in a state of absolute torpidity. This is generally in the mud at the bottom of the water, where they are not only preserved, though at low degree, but also secured from external injury. Here they congregate in multitudes, embracing each other so closely as to appear almost as one continuous mass. On the return of spring they separate from each other, emerge from their places of retirement, and recommence their active life by exercising the important function of reproducing their species." During the breeding-season a warty protuberance is developed on the thumb of the male to assist in holding the female ; and in some foreign species the whole fore-arm becomes enlarged at this time. The spawn is deposited at the bottom of the water, but soon rises to the surface in the well-known glairy masses ; and in due season the tadpoles make their appearance. During the tadpole stage frogs are devoured in large numbers by newts and the smaller fishes ; while in the adult condition numbers fall a prey to the weasel and pole-cat, the heron and other wading birds and the common snake, whose food is almost entirely composed of them. Although the common frog is to a large extent aquatic, it is much less so than the edible species, which inhabits indiscriminately running or still waters, the borders of rivers, rivulets, or streams, lakes or ponds, salt or fresh marshes, or even ditches and pools of water. Owing to the presence of the external sacs, the croak- ing of the male is louder than in the common frog. Both species, like all the more typical representatives of the genus, progress on land by means of leaps ; while in water they swim with the hind-limbs alone. Compared to the bull- frog (R. catesbyana), of Eastern North America, represented in the figure on p. 259, the European frogs are mere dwarfs ; but the largest species of all is Guppy's frog (R. guppyi), from the Solomon Islands, in which the length of the head and body is upwards of 9 inches. The bull-frog is one of those species in which the tips of the toes are pointed, and it is especially characterised by the web extending to the tip of the fourth toe of the hind-foot, the large size of the aperture of the ear, and the relative length of the hind-leg ; the two latter characters distinguishing it from Montezuma's frog (R. montezumce), of Mexico. The body has no lateral glandular fold ; and the vocal sacs of the males are internal. In colour the bull-frog is brown or olive above, with darker marblings ; the under-parts being either uniformly coloured, or marbled with brown. In length it measures from 7 to 7£ inches, exclusive of the legs. More abundant in the southern than in the northern portion of its habitat, the bull-frog is generally met with in rivers and streams well shaded with trees or bushes, where it may be seen in numbers basking in TYPICAL FROGS. 269 the midday sun. Its croaking is said to be louder than that of any other species, and can be heard for a distance of several miles. In the Southern States of America, although most intense during the spring and summer, the croaking is continued throughout the year ; but in the north it is confined to the spring and summer, being especially loud during the breeding-season. It is a remarkable fact that in Canada, at least, the bull-frog passes its first winter in the larval condition, and takes two years to attain its full growth. It may be mentioned that the small Indian frogs forming the genus Oxyglossus differ from the members of the preceding genus by the absence of any notch in the tongue, and the want of vomerine teeth. They are specially interesting on account of being represented by fossil species in the Oxyglossus. JAVAN FLYING 1'ROG (f liat. size). Eocene rocks of Bombay. Fossil frogs belonging to the typical genus Rana occur in the lower Miocene rocks of Europe. " One of the most curious and interesting reptiles which I met Flying Frogs. with in Borneo," writes Mr. Wallace, " was a large tree-frog, which was brought me by one of the Chinese workmen. He assured me that he had seen it come down, in a slanting direction, from a high tree, as if it flew. On examin- ing it, I found the toes very long, and fully webbed to their very extremity, so that when expanded they offered a surface much larger than that of the body. The fore-legs were also bordered by a membrane, and the body was capable of con- siderable inflation. The back and limbs were of a very deep shining green colour, the under surface and inner toes yellow, while the webs were black, rayed with yellow. The body was about 4 inches long, while the webs of each hind-foot, when fully expanded, covered a surface of 4 square inches, and the webs of all the feet together about 12 square inches. As the extremities of the toes have dilated discs 270 FROGS AND TOADS. Madagascar, for adhesion, showing the creature to be a tree-frog, it is difficult to imagine that this immense membrane of the toes can be for the purpose of swimming only, and the account of the Chinaman, that it flew down from the tree, becomes more credible." The species referred to is the Bornean flying frog (Rhacophorus jmrdalis), a member of a large genus, of which another representative (R. rein- ivardti), is shown in the illustration on p. 269. Of the forty-two species of the genus, thirty occur in South and East Asia, and the remaining twelve in While allied in most respects to the water- frogs, they all differ by the presence of a small ad- ditional bone between the terminal and penul- timate joints of the toes, and likewise by the penultimate joints being distinctly marked exter- nally as a kind of ridge ; while they are further mostly characterised by the webbing of the toes of the fore-feet, although the degree to which this is carried is variable. The tips of the toes are always expanded into round discs, and very generally their terminal joints are forked. The males are provided with one or two internal vocal sacs. In habits these frogs are strictly arboreal ; their bright green coloration har- monising with the leaves among which they dwell. The larvae are remarkable for the possession of an adhesive disc behind the mouth on the under surface ; while the muzzle is prolonged into a proboscis, and the single breathing-pore is situated on the right side of the body, nearer to the tail than to the muzzle. Writing of the habits of one of the Cingalese members of the genus (formerly separated as Polypedates), in which the front toes are only half- webbed, Emerson Tennent observes that it " possesses in a high degree, the faculty of changing its hues ; one as green as a leaf to-day will be found grey and spotted like the back to-morrow. One of these beautiful little creatures, which had seated itself on the gilt pillar of a lamp on my dinner- table, became in a few minutes scarcely distinguishable 'in colour from the ormolu ornament to which it clun