CLASS.- -REPTILES. 



Animals 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 y some- 

 times hatched before birth The young resemble the parent, and undergo no trans- 

 formation. 



Section. SHIELDED REPTILES (CATAPHRACTA). 

 Body covered with square imbedded shields. Bones of skulls 

 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. TESTUDINID/E. Feet club-shaped, claws 

 blunt. Shields at tail curved inwards and united together. 

 Neck retractile. 



Genus. TESTUDO. 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 

 movable, plates of breast twelve. Madagascar. 



Family. EMYDIDJE. Head flattened, covered with skin. 

 Neck retractile, vertebrae bent in perpendicular bow. Feet 

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

 Thorax solid, with horny plates. Egg 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. MALACLEMYS. Head with soft skin, toes as in 

 preceding genus. America. 



Genus. CISTUDA. Breastbone divided by a single suture 

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

 America, and Asia. 



Genus. KIXOSTBRNON. Breastbone divided by two cross 

 sutures. Chin bearded. Feet and tail nearly naked. Amer- 

 ica. 



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. CHELIDID/E. 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. 

 Breastbone broad, rounded in front, with a notch behind. 

 Australia. 



Genus. CHELYS. Head very flat, and fringed with wart- 

 like appendages ; nose elongated at proboscis ; jaws with 

 soft lips. Neck thick, flat, long, and bearded at each side. 

 Tail short. South America. 



Family. TRIONYCID^E. Head flat and oval, jaws with 

 hanging fleshy lips, chin not bearded. Neck long and con- 

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



Genus. TYRSE. Ribs eight pair; rest as in Trionyx. 

 Europe, Asia, and Africa. 



Genus. DOGANIA. Head very large, broad behind, narrow 

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

 Asia. 



Family. CHELONIAD^E. Head rounded, shielded ; 

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

 retractile, 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. CAOUANA. 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. CHELONIA. Shell with thirteen smooth shields, 

 not overlapping. First toe clawed. Hot seas. 



Order. EMYDOSAURI. 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 with 

 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. CROCODILID^E. Lower canine teeth fitting 

 into a notch in edge of upper jaw. 



Genus. GAVIALIS. 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. CROCODILUS. Jaws oblong and flat. Nuchal, cer- 

 vical, and dorsal plates separated by little scales. Africa, 

 Asia, and America, 



Family. ALLIGATORID^E. 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 

 substance. Eyelids fleshy. New World. 



Genus. ALLIGATOR. Jaws with small longitudinal ridge 

 between eyes. Hind feet fully webbed. Nostrils separated 

 by division of bony substance. New World. 



Order. AMPHISB^NIA. Body long and cylindrical ; 



Shell covered with hard gristly skin ; breastbone ring-shaped, i covered with squared plates imbedded in the skin, and arranged 



covered with skin, and armed with sharp tubercles in the 



in cross rows. Limbs either wanting or very feeble. Jaws 

 with teeth. 



adult. 



Genus. TRIONYX. Head narrow in front. 



narrow at each end, edge of shield flexible ; eight pair of ribs. jaws. Limbs wanting. Body and chest with similar square 

 North America. ! shields. Pores before vent distinct. 



Breastbone i Family. AMPHISB/ENIDvE. Teeth on inner side of 



