1876.] 405 {Garman. 



poorly furnished with means of locomotion. As it is, the respects in 

 which the fauna of the Isthmus differs are so few, comparatively, as to 

 render very questionable any attempt to treat it as if it were distinct 

 from that of the Amazon- Orinoco region. The study of its Reptiles 

 and Batrachians can only be successfully pursued with continual refer- 

 ence to, and comparison with, those from the south and east. 



Of nineteen species in Mr. Lesley's collection, fourteen are known 

 to be common to the eastern portion of the torrid section, and subse- 

 quent investigations will undoubtedly increase this number. 



REPTILIA. 



Emys venusta Gray. 



Common. Represented in the collection by very young only. 



Ameiva prsesignis B. et G. 



Three specimens. Longitudinal bands very distinct. Preanal 

 plates unlike. Several cephalic plates subdivided in one example. 

 Femoral pores 15, 16, 17. Compared with specimens of A. surina- 

 mensis from Tabatinga, on the upper Amazon, these are stouter and 

 darker in color — more olive and brown. The median dorsal band 

 is not present on the southern specimens, and the upper bands of 

 the sides disappear about the middle of the length of the body ; the 

 spots are much smaller and more separated. Mr. Lesley's specimens, 

 however, do not agree among themselves in regard to the length and 

 distinctness of the dorsal band, and in younger examples it is proba- 

 bly indistinct or absent. 



From the close correspondence in details of squamation and color- 

 ation, it is not at all unlikely that intermediate forms will be found 

 to connect the two as varieties under one species. 



Euprepes bistriatus (Spix) Wagler. 



Spots of brown in the bronze of the posterior half of the back are 

 plentiful. The upper white band on the flank becomes indistinct in 

 the larger examples; that below the brown retains its brightness. 

 Belly bluish white. A tinge of blue in the bronze on the back. 

 Young specimens have fewer spots, less blue on belly and back, and 

 the upper line on the flank is more distinct. 



Iguana tuberculata Laur. 



The green on the backs of the young is so dark that the bands are 

 invisible, those on the tail are indistinct. Half-grown specimens show 

 all the marks distinctly. All have from five to seven bands of black on 

 the throat pouch; these are broken up or lost in the old. On small 



