BATRACHIANS AND REPTILES, CENTRAL AMERICA AND MEXICO. 25 



tioued. The number of suborders is thus eleven, aud the families thej^ embrace num- 

 ber twenty-two. For the characters of five of these families I am indebted largely to 

 Mr. Boulenger. 



As elsewhere, the orders and families of Lacertilia cannot be arranged in a linear 

 series. There are three lines whose terminal groups are the Chamieleontidi«, the 

 Grecconida>, aud the Sciucidte, respecti velj', and between these most of the families can 

 be arranged. The suborders and families are as follows: 

 I. — Prootic not produced beyond arched body ; dentition acrodont ; olfiictory lobes 



not underarched ; two suspensoria ; 

 No clavicle nor mesosternum; no columella; tongue papillose, extremity sheathed. 



I. Ehiptoglossa. 

 A clavicle proximally simple ; an anchor-shaped mesosternum; a columella; tongue 



papillose, not sheathed II. Jcrodonta. 



II. — Prootic bone not produced beyond arched body ; dentition pleurodont ; olfactory 



lobes not underarched ; two suspensoria; 

 A clavicle proximally simple ; an anchor-shaped mesosternum ; a columella; tongue 



papillose, not sheathed III. Iguania. 



III. — Prootic bone produced beyond arched body ; dentition pleurodont, or nearly so; 

 two suspensoria. 

 a Clavicle simple proximally ; olfactory lobes not underarched by frontal. 



Mesosternum cruciform ; tongue papillose IV. Diploglossa. 



aa Clavicle proximally simple ; olfactory lobes underarched by frontal. 



Vertebra', precocious ; tongue smooth V. Thecaglossa. 



Vertebrie amphicoelous ; tongue paiiillose VI. Geccovarani. 



aaa Clavicle proximally expanded ; olfactory lobes underarched by os frontale. 



Tongue papillose or smooth VII. Nyctisaura. 



aaao: Clavicles, when present, expanded proximally; olfactory lobes not under- 

 arched. 

 Clavicles, mesosternum, aud sternum present ; surangnlar distinct : tongue scaly. 



VIII. Leptoglossa. 



Clavicles, mesosternum, and sternum absent; tongue scaly IX. Typhlophthahni. 



IV. — Prootic bone produced beyond arched body; one suspensorium (=opisthotic 



wanting) ; pelvic arch rudimentary or wanting. 

 Frontal bono nuderarching olfactory lobes ; supraoccipital gomi^hosis internal ; no 



orbitosphenoid X. Anguiaauri. 



Frontal bone nuderarching olfactory lobes ; supraoccipital gomi)hosis external ; an 



orbitosiihenoid XI. Oplieosauri. 



The families of those suborders are the following : 



I.— Rhiptoglossa. 



There is but one family of this suborder, the Chamaeleontida}, with the following 

 characters : 



Parietal arch elevated, consisting of the squamosal and parietal bones ; splenial bone 

 none ; toes short, presenting in opposition to each other 1. Chaviwleontidw. 



This family is confined to Africa and Madagascar. 



II.— ACRODONTA. 



But one family represents this suborder. 

 Parietal arch not elevated, consisting of parietal and opisthotic; toes not opposable, 

 directed forwards 2. Jgamidw. 



III. — Iguaxia. 



Surangular boue absent 3. Anolidw. 



Surangular bone present 4. Iguanida. 



