202 REPTILIA: LACERTILIA. XXIX. 



extensible and retractile into a sheath formed by a transverse fold 

 at anterior extremity of posterior part, this sheath disappearing 

 when the tongue is drawn out. Premaxillary single ; dermal cranial 

 ossifications roofing over the temporal fossa ; clavicle slender ; limbs 

 present or absent, the shoulder girdle and pelvis always present ; 

 no abdominal ribs ; bony plates underlying the scales ; vertical plate 

 on head present. Genera 7 ; species 45 ; in warm regions, 

 a. Side with a conspicuous fold ; limbs wanting or the hinder rudimentary ; 

 body snake-like, the tail very brittle ; scales squarish rhomboidal, form- 

 ing straight series, in either direction OPHISAURUS, 296. 



296. OPHISAURUS Daudin. (o<j>is, snake; aavpos, lizard.) 



589. O. ventralis (L.). GLASS SNAKE. JOINT-SNAKE. Green- 

 ish or brownish ; sides largely yellow, with narrow black streaks. 

 Dorsal scales in 14 rows or 120 transverse series ; 10 rows on belly ; 

 scales on back obtusely keeled, others smooth ; ear much larger than 

 nostril. L. 25. Wis. to Kan. and S. 



FAMILY CXVI. IGUANIDJB. (THE IGUANAS.) 



Tongue thick, villous, nearly or quite entirely fixed to the floor 

 of the mouth, and little if at all notched in front ; pupil round ; eye- 

 lids well developed; scales various, those on head usually small ; 

 head generally with an enlarged interparietal scale ; teeth subequal. 

 Habits various, mostly insectivorous. A very large family of 50 

 genera and 320 species, swarming in the hotter parts of America ; 

 a very few in the East Indies. 



a. Femoral pores absent; toes dilated or depressed, the distal joint narrower, 

 cylindrical or compressed, raised above the one before it ; scales small 

 or granular ; tf with an inflatable gular sac ; tail long, not prehensile ; 

 lateral teeth tricuspid; no sternal fontanelle ; tympanum distinct. 



ANOLIS, 297. 



aa. Femoral pores present ; fourth toe longer than third ; lateral teeth tri- 

 cuspid. 



b. Head without spines ; no dorsal crest; occipital scale very large, 

 c. Gular folds 2, the second denticulated ; dorsal scales minute, uniform ; 

 caudal scales small ; tympanum concealed. . . HOLBROOKIA, 298. 

 cc. Gular folds none; tympanum distinct; scales keeled, equal; no crest. 



SCELOPORUS, 299. 



bb. Head armed with bony spines; body short, depressed; a large sternal 

 fontanelle; scales unequal PHRYNOSOMA, 300. 



297. ANOLIS Daudin. 



590. A. principalis (L.). "CHAMELEON." Grass-green ; head 

 brownish, the color changing at times in life to grayish, yellowish, 

 bronze, and black ; gular sac crimson when inflated ; head scales 

 large and rough; scales of body subequal, keeled. L. 6. Pine 

 woods, Tenn. to Cuba ; common S. ; one of the most beautiful of 

 lizards. (A. carolinensis Cuvier.) 



