212 DR. H. GADOW ON MEXICAN [June 6, 



two Asiatics of the same genus. But Coleonyx elegcms is distinctly 

 a forest form. I found it a few miles from the coast of Guei-i-ero 

 in a moist patch of thick lowland forest on the ground under 

 stones and rotten stumps. A typical Central American, ranging 

 through the Pacific and Atlantic Tierra Caliente of Mexico, from 

 which country it had hitherto been recorded only by Sumichrast 

 from near Orizaba ; extending south to Costa Rica. 



Iguanid^ t. — It is not profitable to speculate upon the original 

 home of this family. The overwhelming majority of genera and 

 species is American, from Mexico to Brazil, It is well known that 

 the Galapagos possess the semimaiine Amhlyrhynchus and Cono- 

 lo2)hiis, that a few species occur in Madagascar, and Brachylophus 

 fasciatus in the Viti and Tonga Islands ; further, that an Iguanid 

 allied to the genus Iguana existed in the Eocene or Oligocene of 

 Europe, and that therefore attempts have been made to explain 

 the present scattered distribution of the family by a formerly 

 subuniversal range ; in other words, they are a very ancient 

 group. 



Concerning America, it is significant that only a few species of 

 Sceloporus and Plirynosoma extend into the United States, 

 although far northwards. Of the large genus AnoUs, only 

 A. carolinensis enters Texas to Carolina, but it is also found in 

 Cuba. 



Mexico itself, Centi-al America, and the Antilles are rich in 

 genera and species. These Iguanid^e can be divided into two 

 groups : — 



A Sonoran set, comprising genera which are essentially xero- 

 phile and humivagous, with depressed bodies and short tails. 

 None of these reaches far into Central America, and none has 

 entei-ed the Antilles. Crotajihytiis, Holhrookia, Uta, Phrynosoma, 

 Sceloporus, which, in the order mentioned, extend from California 

 and Arizona southwards, with decidedly Pacific or Western pre- 

 dilection ; only a few Scelop)on(,s, those which have spread into 

 the Atlantic Tierra Caliente, continife further into Central 

 America. Nearly all these southern Scelojionts are fitted for 

 arboreal life, less depressed in body, and suited to a moist climate, 

 be this hot or cool. They lead thereby to the second set, which 

 are essentially arboreal, mostly inhabitants of forests or of rocky 

 bush-land ; all southerners, with their centre in Central and 

 South America, extending into the Mexican Tierra Caliente, with 

 prevalence on the Atlantic side, and two * have allied genera or 

 species in the Antilles : Anolis*, Iguana* , Basiliscus, Lmmanctus, 

 Corythoplianes, and Ctenosaura. 



Of course there are transitional forms, for instance the genus 



f Iguana, or Guana, is a native word applied to the Iguana ; but where this does 

 not occur, the name is given to Ctenosaura, for instance at Cuernavaca. The 

 Zapotec name of Ctenosaura is Tilcampo ; Basiliscus and Corythophanes are called 

 Teterete. At Rio Balsas, scaly lizards, e.g. Sceloporus, are distinguished as 

 Chintete. 



