DEFINITIONS OF SYSTEMATIC NAMES 



419 



Hatteria, another name for Sphenodon. 



Heloderma, poisonous lizard from Ari- 

 zona; Gila monster. 



Heptanchus, primitive shark with seven 

 gill slits. 



Hexanchus, primitive shark with six gill 

 slits. 



Holocephali, order of shark-like fishes; 

 Chimsera. 



Hypogeophis, genus of Caecilians. 



Hyracoidea, order of mammals including 

 Hyrax. 



Ichthyophis, genus of caecilians from Cey- 

 lon. 



Ichthyopsida, group of vertebrates which 

 have gills; fishes, amphibia. 



Ichthyosaurs, extinct aquatic reptiles. 



Iguana, genus of tropical American lizards. 



Insectivores, order of small mammals; 

 moles, shrews, etc. 



Inuus, genus of macaques including the 

 Barbary ape. 



Lacerta, genus including the common 

 lizards of Europe. 



Lacertilia, sub-order of reptiles including 

 all lizards. 



Lagenorhynchus, a genus of dolphins. 



Lepidosiren, genus of lung fishes (dipnoi) 

 from South America. 



Lepidosteus, genus of ganoid fishes, gar- 

 pike. 



Lopholatilus, genus of teleosts from Gulf 

 Stream; tile fish. 



Macropus, genus of marsupials; kangaroos. 

 Mammals, class of vertebrates, with hair, 



nourishing the young with milk. 

 Manatus, genus of sirenians, manatees. 

 Manis, genus of old-world edentates; 



scaly ant-eaters. 

 Marsupialia, sub-class of mammals with 



pouch for young, opossums, kangaroos, 



etc. 

 Megalops, genus of fishes including the 



tarpon. 

 Melanerpeton, genus of extinct stego- 



cephal amphibians. 

 Monodelphia, sub-class of mammals, in* 



eluding all except monotremes and 



marsupials. 



Monotremata, sub-class of mammals with 

 cloaca; includes duckbill and Echidna 

 of Australia. 



Morones, genus of catfishes. 



Mugil, genus of fishes, mullets. 



Mustelus, genus of small sharks; dogfish. 



Myrmecobius, genus of Australian mar- 

 supials. 



Myxine, genus of cyclostomes; hag fishes. 



Myxinoids, group of cyclostomes; hag 

 fishes. 



Necturus, genus of aquatic amphibians 

 \yith tail and external gills, central U. S. 



Notidanids, sub-order of sharks with more 

 than five gill clefts. 



Nototrema, genus of South American toads 

 with dorsal brood sac. 



Ophidia, sub-order of reptiles; snakes. 



Opisthocomus, South American bird, type 

 of a separate sub-order. 



Opisthodelphys, genus of tropical Amer- 

 ican tree-toads. 



Omithorhynchus, genus of monotremes; 

 duckbill of Australia. 



Ostariophysi, bony fishes with Weberian 

 apparatus. 



Ostracoderms, a group of extinct verte- 

 brates of very uncertain position. 



Palaeohatteria, a fossil reptile allied to 



Sphenodon. 

 Palaeospondylus, a problematical fossil 



vertebrate from Scotland. 

 Perennibranchs, tailed amphibia which 



retain the gills through life. 

 Perissodactyls, sub-order of mammals with 



odd number of toes; horses, rhinoceros, 



tapirs. 

 Petrobates, genus of extinct theromorph 



reptiles. 

 Petromyzonts, sub-class of cyclostomes, 



lampreys. 

 Phoca, genus of carnivores including com- 

 mon seals. 

 Physodisti, fishes in which the air-bladder 



is closed. 

 Physostomi, g^oup of fishes in which the 



air-bladder has a duct; mostly fresh 



water. 

 Pipa, tongueless toad from South America. 



