KEY TO THE PRINCIPAL SPECIES OF LIZARDS 

 AND CROCODILIANS 



1. Without legs 2. 

 With legs 5. 



2. No external ear openings or eyes; body apparently scaleless, with ring- 



like creases like an earthworm; Florida; Family Amphishaenidae 

 (part) 



Rhineura floridana (Baird) Florida Worm Lizard 

 Either with external ear openings, eyes or visible scales 3. 



3. With ear openings; eyes with movable lids; tail longer than body (when 



complete) ; Virginia to Wisconsin, southward to Florida and N. M. 

 Ophisaurus ventralis (Linn.) Glass Snake 

 (of Family Anguidae) 

 Without ear openings; eyes covered with thin skin; tail shorter than 

 body; California; Family Anniellidae 4. 



4. Back silvery or buff 



Anniella pulchra pulchra Gray Silver California Worm Lizard 

 Back dark brown 



Anniella pulchra nigra Fischer Black California Worm Lizard 



5. With but one pair of legs, placed anteriorly; restricted to Lower Cali' 



fornia; Family Amphishaenidae (part) 



Bipes hiporus (Cope) Two-legged Lizard 

 With two pairs of legs 6. 



6. Anus running lengthwise; Family Crocodylidae (of Order Loricata) 



Crocodilians 7. 



Anus running crosswise 8. 



7. Snout very narrow and pointed; Florida; almost exterminated 



Crocodylus acutus Cuvier Crocodile 

 (Crocodilus americanus (Laurenti) ) 

 Snout wider and rounded; N. C. to Florida and Texas 

 Alligator mississipiensis (Daudin) Alligator 



8. Body very fat, toad-Hke; head with spines or knobby tubercles; Family 



Iguanidae (part) Horned Lizards (Frogs, Toads) 9. 



Body more slender, lizard-like; head without spines or tubercles (the 



neck may or may not be spiny) 17. 



9. Sides relatively smooth; tympanum or ear membrane covered with scales; 



Ariz, to Texas 



Phrynosoma modestum Girard Little Homed Lizard 

 (Anota modesta of Cope) 

 With one or two rows of enlarged scales along each side; tympanum 

 hidden or variously exposed 10. 



10. Head spines obsolete; scales of belly well keeled; S. Ariz. 



Phrynosoma ditmarsi Stejneger Ditmars' Horned Lizard 

 Head spines present; scales of belly variously keeled to smooth 11. 



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