78 PEPTILES. 



pi. 1. Blackish; four toes like the large one, but the branchial 

 tufts are less fringed ; its length does not exceed one foot. 



S. striata, Le Conte, lb. I, pi. 4. Blackish; two longitudinal 

 yellow streaks on each side ; only three toes ; the branchial tufts 

 but slightly fringed ; length nine inches*. 



* The branchiae of these two species have been considered as taking no part in the 

 process of respiration, in consequence of which M. Gray has formed a genus for them, 

 which he calls PsEUDOBRANCHUs; it is easy, however, on their inferior surface, to 

 see folds and a vascular apparatus, whose use is, to us, verj' plain ; besides this, the 

 observations of Major Le Conte demonstrate the fact, that these sirens, like the li- 

 zard sirens, are perfect animals. 



