276 ZOOLOGY. 
provided with large labial and submaxillary scales. The teeth are variously 
shaped and arranged, generally, however, inserted on the internal margin of a 
common maxillary groove. Sometimes they are found in the palate. The 
tongue is free, fleshy, flat, more or less extensible, the base sometimes con- 
tained in a sheath, the apex always emarginate, sometimes deeply cleft. The 
tail is very long and conical, the scales arranged in regular rings or whorls. 
The skin is sealy, without projecting crests; the dorsal scales variable; the 
central plates always larger, rectangular or rounded. Most of the species 
exhibit femoral pores. 
The Lacertide, like several other families of Sawria, are extensively dis- 
tributed. About one third of the entire number of species belongs to America ; 
only one, however, is found to North America. Somewhat the largest propor- 
tion occurs in Africa; Europe comes next in point of numbers. About 70 
Species in all are known to naturalists. Some occur in a fossil state, but, for 
the sake of greater convenience, we shall refer to all of the lacertoid species 
when we come to consider the Varanida. 
The Lacertide may be conveniently divided into two sub-families, the 
Pleodontes and the Celodontes. In the Pleodontes, the teeth are entirely 
solid, without any internal cavity; and attached by the bases and external 
faces to the inside of the maxillary bones. They are usually bent a little out- 
wards, especially those more anterior. All the species of pleodont lizards 
belong to the New World. There are two strongly marked divisions of the 
sub-family ; the one with the tail compressed, the other with it conical. 
Those with compressed tails exhibit a striking resemblance to the crocodiles, 
which is not diminished by their great size. The tail, flattened like an oar, 
and with the surface increased still more by caudal crests, enables these ani- 
mals to move with great readiness in the water, which they inhabit to as great 
an extent as the crocodiles. heir feet, like those of these latter animals, are 
palmated. The Tupinambis of some writers is the Crocodilurus lacertinus, a 
gigantic species nearly six feet in length, inhabiting the waters of Brazil and 
Guiana. Thorictes dracena, found in Guiana, is still larger, individuals of 
almost seven feet in length being known. Here the tail alone occupied nearly 
five feet. 
The section of Pleodonts, embracing species with conical tails, is more ex- 
tensive than the last. Here the animals are more terrestrial or arboreal. A 
single genus, Aporomera, is entirely destitute of femoral pores. Acrantus, a 
large South American genus, has but four toes visible on the hinder feet. 
The other forms represent no remarkable deviation from the usual structure. 
The genus Salvator (pl. 74, fig. 80) includes the true Twpinambis or Sauve- 
gardes. Individuals of eight feet in length are not uncommon. ‘The genus 
Cnemidophorus is interesting as containing the only representative of the 
Lacertidee in North America. This species (C. sex-lineatus) occurs abun- 
dantly in the Southern States, and as far north as north-eastern Maryland. 
It is readily distinguishable from the other lizards by the six yellow lines 
along the back, and the long tail. When pursued, it runs with incredible 
swiftness, climbing trees with great facility, but not leaping from branch to 
branch, like the green lizard, Anolis carolinensis. | 
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