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CHAP. XIV.] THE NEOTROPICAL REGION. 11
Celestus and Diploglossus (Scincidse) ; Sphcerodadylus (Gecko-
tidse) ; Lioccphalus, Liolcemus, Proctotretus, and many smaller
genera (Iguanidse). The three extensive Old World families
Varanidse, Lacertidae, and Agamidse, are absent from the entire
American continent.
In the order Crocodilia, America has the peculiar family of
the alligators (Alligatoridse), as well as several species of true
crocodiles (Crocodilidae). The Chelonia (tortoises) are repre-
sented by the families Testudinidas and Chelydidae, both of wide
range ; but there are six peouliar genera, Dermatemys and Stan-
rotypus belonging to the former family, Peltocephalus, Podo-
cnemis, Hydromedusa, and Chelys, to the latter. Some of the
Amazon river-turtles of the genus Podocnemys rival in size the
largest species of true marine turtles (Cheloniidse), and are equally
good for food.
Amphibia.—The Neotropical region possesses representatives
of sixteen, families of Amphibia of which four are peculiar ; all
belonging to Anoura or tail-less Batrachians. The Cseciliadee
or snake-like amphibia, are represented by two peculiar genera,
Siplwnopsis and Bhinatrema. Tailed Batrachians are almost
unknown, only a few species of Spelerpes (Salamandridse) enter-
ing Central America, and one extending as far south as the
Andes of Bogota in South America. Tail-less Batrachians on
the other hand, are abundant ; there being 14 families repre-
sented, of which 4,—Ehinophryndse, Hylaplesidae, Plectroman-
tidse, and Pipidse are peculiar. None of these families contain
more than a single genus, and only the second more than a
single species ; so that it is not these which give a character to
the South American Amphibia-fauna. The most important and
best represented families are, Eanidae (true frogs), with eleven
genera and more than 50 species ; Polypedatidae (tree-frogs)
with seven genera and about 40 species ; Hylidae (tree-frogs)
with eight genera and nearly 30 species ; Engystomidse (toads)
(5 genera), Bombinatoridse (frogs), (4 genera), Phryniscidae and
Bufonidae (toads), (each with 2 genera), are also fairly represen-
ted. All these families are widely distributed, but the Neotropi-
cal genera are, in almost every case, peculiar.