xvi REPTILES, AMPHIBIANS AND FISHES 



pLATE FACING PAGE 



X. A, Glass-snake to illustrate the assumption by lizards of the glid- 

 ing type of conformation characteristic of snakes. B, Ring- 

 snakes hatching XI 3 



A. Photo, Lewis Medland. 



B, Photo, W. S. Berridge. 



XI. S-necked (Cryptodiran) Tortoise (Horuopus arcolatus), to show 

 how the head is withdrawn by a vertical S-like curve. Side- 

 necked (Pleurodirati) Tortoise (Stcrnothocrus niger), to show 

 how the head is withdrawn by a lateral flexure of the neck. (By 

 permission of the Trustees of the British Museum) . . . 127 



XII. A, Head of African Puff-adder (Bitis arietans), showing poison 



fangs. B, Poisonous lizard (Heloderma suspectum) of Arizona . 144 



A, Photo, W. S. Berridge. 



B, Photo, Lewis Medland. 



XIII. A, Crested Newt (Molge cristatus), male. B, Ditto, female. C, 



Bull-frog (Rana catesbiana) ....... 162 



C, Photo, Lewis Medland. 



XIV. A, Proteus an^uinus. B, Amphiuma means. C, Siren lacertina 164 



A, Photo, W. S. Berridge. 



B and C, Photos, Lewis Medland. 



XV. A, Smooth-clawed Toad (Xenopus l&vis), dorsal aspect. B, Same, 



ventral aspect. C, Common Toad (Bufo vulgaris) . . . 167 

 Photos, Lewis Medland. 



XVI. A, Surinam Toad (Pipa americana), female with young escaping 

 from cells in skin of back. B, Nototrema marsupiatum, with 

 dorsal pouch half developed. C, Same with pouch full of eggs . 195 



XVII. A, a worm-like Amphibian (Ickthyophis glutinosus) with eggs. 

 B, Embryo of same taken from egg, magnified. C, Embryo 

 just before hatching, magnified ....... 206 



XVIII. A, Axolotl, albino specimen. B, Intermediate stage in metamor- 

 phosis of Axolotl. C, Fully developed Amblystoma tigriuum . 212 

 A, Photo, W. S. Berridge. 



XIX. A, Hyla baudini, a Tree-frog of Nicaragua ; an example of pro- 

 tective coloration. B, Bombinator igneus, the fire-bellied Toad, 

 showing warning coloration and warning attitude . . . 220 

 From a drawing in colour by James Green. 



XX. A, The African fringe-finned Ganoid, Polypterus bichir. B, Com- 

 mon Sturgeon, Acipcnsev sturio. C, American Bony-pike, 

 Lepidosteus osseus ......... 240 



Photos from stuffed specimens in the British Museum. 



XXI. A, Hammer-headed Shark. B, Head of Chlamy doselachus 

 anguineus, after Garman, showing the six gill-slits. C, 

 Chimara colliei. Alter Bashford Dean ..... 253 



XXII. Map of the World on Mercator's projection, showing Distribution 



of Fishes 266-267 



XXIII. A, Arapaima gigas. B, Galeichthys assimilis, a Central Ameri- 



can Siluroid. C, Hydrocyon goliath, an African Characinid . 268 

 A, Photo from specimen in Natural History Museum. 



XXIV. Frontispiece. 



