GLASS— REPTILES. 



Avimals with distinct bony skeleton — Skin clothed with horny plates or scales, covered with thin epidermis; 

 often, shed periodically — Respiration by lungs — Heart with two auricles; single ventricle divided into 

 cells — Young produced from eggs; sometimes hatched before birth — The young resemble the parent, and 

 undergo no transformation. 



Section. SHIELDED REPTILES Cataphracta).— 



Body covered with square imbedded shields. Bones of skull 

 thick, hard, and united into solid mass. Bones of jaws united 

 and solid. Young hatched after birth by egg. 



Order. CHELARIANS. — Body enclosed in a case formed of 

 the bones of the thorax, the limbs and head protruding. Jaws 

 without teeth, and covered with horny coat. 



Family. TESTUDINIDiE.— Feet club-shaped, claws blunt. 

 Shields at tail curved inwards and united together. Neck re- 

 tractile. 



Genus. Tkstudo. — Thorax convex, rather globular, and 

 solid. Breastbone solid, with twelve shields; those of the 

 throat separated. Five toes on fore feet, four on the hinder pair. 

 Most warm parts of the world. 



Genus. Pyxis. — Thorax solid. Front lobe of breastbone 

 moveable, plates of breast twelve. Madagascar. 



Family. EMYDIDiE —Head flattened, covered with skin. 

 Neck retractile, vertebra? bent in perpendicular bow. Feet flat 

 and broad, claws sharp. Tail conical and shielded beneath. 

 Thorax solid, with horny plates. Fgg oblong and white. 



Genus. Emys. — Head and tail moderate. Breastbone solid 

 and deeply notched behind. Head with thin hard skin. Toes, 

 five on fore limbs, four on hind pair, webbed to claws. Europe, 

 Africa, Asia, and America. 



Genus. Mai. aci, emys. — Head with soft skin, toes as in pre- 

 ceding genus. America. 



Genus. Cistuka. — Breastbone divided by a single suture, 

 across the centre, and rounded in front. Southern Europe, 

 America, and Asia. 



Genus, KlNOSTERNON. — Breastbone divided by two cross 

 sutures. Chin bearded. Feet and tail nearly naked. America. 



Genus. Chelydra. — Head very large, covered with hard 

 wrinkled skin. Breastbone slender, sharp at each end, cross- 

 like and leathery in the middle. Chin with two beards. Tail 

 crested. America. 



Family. CHELIDIDJE.— Head flat, broad ; nostrils long and 

 tubular ; jaws horny. Neck long, and bent under side of shell 

 during repose. Feet webbed, and lobes between the claws ; 

 claws long and sharp. Shell rather flat. Pelvis large. 



Genus. CHELODINA. — Head large and lengthened ; neck very 

 long, covered with thin skin. Claws, four on each foot. Breast- 

 bone broad, rounded in front, with a notch behind. Australia. 



Genus. CHELTS. — Head very flat, and fringed with wart-like 

 appendages; nose elongated at proboscis; jaws with soft lips. 

 Neck thick, fiat, long, and bearded at each side. Tail short. 

 South America. 



Family. TRIONTCIDJE. Head flat and oval, jaws with 

 hanging fleshy lips, chin not beamed. Neck long and contrac- 

 tile. Toes, five on each foot; claws, three. Tail short. Shell 

 Voi, III — 77. 



covered with hard gristly skin; breastbone ring-shaped, covered 

 with skin, and armed with sharp tubercles in the adult. 



Genus. Tkionyx. — Head narrow in front. Breastbone nar- 

 row at each end, edge of shield flexible ; eight pair of ribs. 

 North America. 



Genus. Tyksk. — Ribs, eight pair ; rest as in Trionyx. Eu- 

 rope, Asia, and Africa. 



Genus. Dooania. — Head very large, broad behind, narrow 

 in front. Ribs, eight pair, united into solid disc when adult. 

 Asia. 



Family. CHELONIADa:. — Head roundel, shielded; jaws 

 naked and horny. Feet very long, front pair largest, not re- 

 tractile, flat, and pin-shaped ; toes expanded at tips. Tail short 

 and thick. Ribs free at end. Breastbone, ring-like, united to 

 thorax by gristly suture. 



Genus. Sphargis. — Shell with leathery skin. Claws want- 

 ing. West Indies. 



Genus. Caouaxa — Shell with at least fifteen horny shields. 

 Breastbone with a strong keel. Claws wanting. Atlantic and 

 most warm seas. 



Genus. Caretta. — Shell with thirteen overlapping shields. 

 Breastbone keeled on both sides. First or two first toes with 

 claws. American and Indian seas. 



Genus. Cheloxia. — Shell witli thirteen si >th shields, not 



overlapping. First toe clawed. Hot seas. 



Order. EMYDOSAU Rl.— Body elongated and covered with 

 bony plates, arranged in longitudinal rows. Limbs four in 

 number and free. Jaws with teeth, inserted in sockets and 

 replaced by others formed below them. Back of neck witli two 

 sets of bony plates, the first called nuchal, second cervical. Toes, 

 four on fore legs, five on hinder pair; claws on three inner toes. 



Family. CROCODILIDiE.— Lower canine teeth fitting into a 

 notch in edge of upper jaw. 



Genus. Gaviai.is.— Teeth all same length; jaws very long 

 and slender, and rounded; nose of male inflated. Plates of back 

 and cervicle set united. Asia. 



Genus. MeCISTOPS. — Teeth, ninth of upper jaw and eleventh 

 of under larger than others; jaws oblong, slender, and rather 

 flat; nose not swollen. Cervical and dorsal plates united. 

 Hind feet webbed. Africa. 



Genus. CroCODILOS.— Jaws oblong and flat. Nuchal, cervi- 

 cal, and dorsal plates separated by little scales. Africa, Asia, 

 and America. 



FamUy. ALLIGATORIDJE.— Canine teeth of lower jaw fitting 

 into a hollow in edge of upper jaw. 



Genus. Yacare.— Jaws with ridge across face. Hind feet 

 little webbed. Nostrils separated by division of gristly sub 

 stance, Eyelids fleshy. New World. 



> 



