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Sirenia, order of marine mammals; 
manatees and dugongs 
Sirenoidea; order of lung-fishes, containing 
the living species. 
Spalacotherium, genus of extinct mammals. 
Sphenodon, genus of lizard-like reptiles 
from New Zealand; order Rhyncho- 
cephalia. Z 
Squamata, order of reptiles including snakes 
and lizards. 
Stegocephala, order of extinct amphibians. 
Stegosaurs, family of extinct dinosaur 
reptiles, 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 skeleton, 
including all common fishes. 
Testudo, genus of land turtles. 
Testudinata, turtles, same as a 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. 
DEFINITIONS OF SYSTEMATIC NAMES. 
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. 
Typhlopide, family of peculiar’ tropical 
serpents, 
Ungulates, order of mammals which walk 
on the tips of the toes; horse, cattle, deer, 
antelope, etc. 
Urodeles, order of tailed amphibia. 
Varanus, genus of lizards from Africa. 
Xenarthra, sub-order of American edentates, 
ant-éaters and armadillos. 
Xenopus, genus of tongueless toads from 
Africa, 
Zeuglodon a genus of extinct whales 
(Cetacea). 
Ziphius, genus of toothed whales. 
