CROCODILIANS, LIZARDS, ANt> 8NAKES. 509 



AA. One pair of prefioiitonasal plates. 

 a Two loreals. 



/i Lateral prelroutonasals present. 



Lateral prelroutonasals large; projecting snpraanricular scales; 

 nnclial scales in six rows; green, with angular brown cross bands. 



G. vasconcclosii Bocourt. 

 Lateral prefrontouasals small; no projecting snpraauricular scales; 

 nnchal scales in six rows; green, with brown cross bands. 



G. tdiiiatiiii Wiegniann. 

 y^/iNo lateral prefrontonasals (postnasals present). 



Six rows nnchal scales; above dark brown with transverse series of 



yellow spots G. deppel Wiegmann. 



Four rows of nnchal scales; no grannies in lateral fold, which does 

 not extend on neck; green, with black reticulations on scales. 



G. oaxacw Giinther. 

 Four rows of nuchal scales; granules in lateral fold, which extends 

 on neck ; green ; scales with black reticulations. 



Gf, gramineus Cope. 

 II. I )orsal scales equal or smaller than ventrals. 

 A. Two pairs of iirefrontonasal scuta. 

 a Two loreals. 



Lateral prefrontonasals, postnasals present; scales keeled, iu from 

 49 to 55 transverse series on body, and 10 longitudinal rows on 

 nape; above brown with more or less complete cross bands of 

 black and white spots; form elongate.. G, liocephahis Wiegmann. 

 Lateral prefrontonasals and postnasals present; scales smooth in 

 16-18 longitudinal series; above brown, with yellowish-white 

 rhombs on body; toj) of head yellowish white. G. rhombifer Peters. 

 a a One loreal. » 



Postnasals present ; no lateral prefrontonasal ; scales smooth in 10- 



12 longitudinal series; browu, sides darker G. modestus Cope. 



A A. One pair of prefrontonasal scuta. 

 LX Two loreals. 



/i Lateral prefrontonasals present. 



Lateral prefrontonasals small ; scales, only six or eight median rows, 

 obtusely keeled, nuchals smooth, ten or twelve rows; light brown, 



with well-spaced dark-brown cross bands G. kiiiffii Gray. 



Lateral prefrontonasals small ; all scales strongly keeled, nuchals 

 in 10 rows; prefrontals in contact; light brown with 7 dark-brown 



cross bands on body G. muUicdr'niatus ' Blainvllle. 



Lateral prefrontonasal small; all scales smooth or obsoletely keeled; 

 nuchals in about 12 rows; yellowish olive, with 10 cross bands on 



body G. 7iohilis Bairtl and Girard. 



/3/i No lateral prefrontonasals. 



No postnasals; scales strongly keeled, nuchals iu 12 longitudinal 

 rows; 10 upper labials; dark brown, with ten to twelve darker 



cross bands on body G. burtietiii Gray. 



Postnasals present; scales weakly keeled, 10 nuchal rows; 11 upper 

 labials; light brown, no cross bands; small lateral spots. 



G. jiriiicipi'i Baird and Girard. 

 act One loreal (no lateral prefrontonasals; postnasals present). 



Twelve nuchal rows, with all the dorsals, keeled; 11 ui)per labials; 

 brown, with 10-12 darker bands; below olive.. G. bttrnettii Graj. 



' Inferior postnasal sometimes wanting. 



