420 



DEFINITIONS OF SYSTEMATIC NAMES 



Pisces, the class of fishes. 



Placentalia, all mammals (except marsu- 

 pials and monotremes) in which a pla- 

 centa occurs. 



Placodus, genus of extinct theriomorph 

 reptiles. 



Plesiosaurs, order of extinct, long-necked 

 swimming reptiles. 



Polyodon, genus of ganoid fishes, paddle 

 fish. 



Polypterus, genus of ganoids from Africa. 



Porichthys, genus of fishes from Pacific; 

 midshipman. 



Primates, highest order of mammals, .in- 

 cluding monkeys, apes and man. 



Pristiurus, genus of European dogfish. 



Proboscidea, order of mammals, including 

 elephants. 



Procolophon, genus of extinct theromorph 

 reptiles. 



Proteus, genus of tailed amphibians from 

 caves of Austria, allied to Necturus. 



Protopterus, genus of dipnoi from Africa. 



Psittacus, genus of parrots. 



Pterodactyls, extinct flying reptiles. 



Pterosaurs, extinct flying reptiles, ptero- 

 dactyls. 



Pythonomorphs, a group of extinct swim- 

 ming reptiles. 



Raia, genus of elasmobranchs, including 

 the skates. 



Rana, genus of amphibia, frogs. 



Ratitas, birds without keel to sternum, 

 ostriches. 



Rhea, three-toed South American ostrich. 



Rhynchobatus, genus of tropical skates. 



Rhynchocephalia, order of lizard-like rep- 

 tiles; Sphenodon of New Zealand only 

 living species. 



Rodentia, order of mammals with gnawing 

 teeth, rats, rabbits, beaver. 



Ruminants, group of ungulate mammals 

 which chew the cud. 



Salamandra, genus of tailed amphibia 



from Europe. 

 Salamandrina, order of tailed amphibians 



without gills. 

 Salmonids, family of fishes including trout 



and salmon. 

 Sauropsida, class of vertebrates including 



reptiles and birds. 



Sceloporus, genus of lizards of eastern 

 United States. 



Scomber, genus of fishes; mackerel. 



Scorpaenichthys, genus of sculpins. 



Selachii, order of elasmobranchs; sharks. 



Serranidae, family of marine, j)erch-like 

 fishes. 



Siluroids, order of fishes containing the 

 cat-fishes. 



Siren, genus of tailed amphibian from 

 U. S. with external gills. 



Sirenia, order of marine mammals; 

 manatees and dugongs. 



Sirenoidea; order of lung- fishes, contain- 

 ing the living species. 



Spalacotherium, genus of extinct mam- 

 mals. 



Sphenodon, genus of lizard-like reptiles 

 from New Zealand; order Rhyncho- 

 cephalia. 



Squamata, order of reptiles including 

 snakes and lizards. 



Stegocephala, order of extinct amphib- 

 ians. 



Stegosaurs, family of extinct dinosaur rep- 

 tiles, some very large. 



Stenops, genus of lemurs. 



Stenostomus, genus of fishes; scup. 



Teleostomes, fishes with true jaw, includes 



ganoids and teleosts. 

 Teleosts, order of fishes with bony skele- 

 ton, including all common fishes. 

 Testudo, genus of land turtles. 

 Testudinata, turtles, same as Chelonia. 

 Tetrapoda, term to include amphibia, 



reptiles, birds, and mammals, which 



have feet in place of fins. 

 Theromorpha, extinct reptiles, forming the 



lowest order of the class. 

 Tinnunculus, genus of hawk-like birds; 



kestrel. 

 Torpedo, genus of skates with remarkable 



electric powers. 

 Trionyx, genus of fresh-water turtles. 

 Triton, genus of tailed amphibian, aquatic, 



European. 

 Tropidonotus, genus of snakes, including 



our water snake. 

 Trygon, genus of skates, string-rays. 

 Typhlopidae, family of peculiar tropical 



serp>ents. 



