ORDER II. 
SAURII. 
FAMILY II. 
IGXJANIDAE. 
Char. 1. The body is covered above with horny plates or scales, which are without knobs or 
tubercles ; most commonly, however, there is either a dorsal or caudal crest. The abdomen is 
covered with small plates. 
Char. 2. The head is destitute of large plates. 
Char. 3. The eyes are furnished with two moveable lids. 
Char. 4. The teeth are placed sometimes in a common socket or groove ; at others they are 
not set in the bone, but only united firmly to its free border. 
Char. 5. The tongue is thick, fleshy, flattened, and covered with papillae; is destitute of a 
sheath at its root, and is only movable at its tip. 
Char. 6. The fingers and toes are free, distinct, of unequal length, and are all furnished with 
nails. 
The family Iguanidae , according to Dumeril and Bibron, includes about forty six genera 
arranged in two sub-families or sections : 
I. Teeth mostly conical, and received in a cylindrical groove of the jaws. 
II. Teeth solidly united to the most prominent part of the jaws, which offer no groove. Four 
genera only of this family are found within the limits of the United States, viz: Anolius, Tropi- 
dolepis , Crotaphytus, and Phrynosoma. —(Holbrook, 1842.)* 
Gen. URO-SAURUS, Hallo well. 
Gen. Char. — Body very slender, which, as well as the head, is much depressed ; tongue 
‘triangular, slightly nicked in front, deeply notched behind, free anteriorly, not enclosed in a 
sheath ; teeth sharp pointed, conical, the posterior ones tricuspid, situated on the inner side of 
the jaw; scales upon the back large, hexagonal, strongly carinated, much larger than those upon 
the sides, which are granular; scales of abdomen smooth; nostrils superior, in a single scale; 
head covered with polygonal plates of unequal size ; aural apertures very distinct; a transverse 
gular fold; extremities slender ; toes, 5-5 ; tail very long and tapering, verticillate ; femoral 
pores, but no anal ones. 
URO-SAURUS GRATIOSUS, Nob. 
Syn. Ula ornata, Baird & Girard, Proceed. A. N. S. vol. VI, p. 126. 
Sp. Char.— Head yellow, with a few brownish marks; seven longitudinal rows of hexagonal 
0 Others have since been added, as Uro-saurus, Dipso-saurus, Anoia, &c. 
