ALLIGATORS. 



65 



Syn. 62. Dum. et Bib. iii. 79. Wagler, Syst. 140, t. 8,/. 1. bat- 

 terer, Ann. Mus. Vien. t. 23. C. Yacare, Daud. Rept. ii. 407. C. 

 Americamis, Laur. Seba, t. 104,/. 10. C. Caiman, Daud. 



Head elongate; muzzle flat, moderately enlarged, frontal ridge 

 very slightly sinuate, preorbital ridge to the edge of the jaws; max- 

 illary pits 3-3 ; upper part of the upper eyelids finely striated ; 

 nuchal shields many, in 2 series ; cervical, small, oval, elevated 

 much compressed scales, in 4 or 5 rows ; dorsal plate obtusely 

 keeled, the two vertebral series nearly flat, forming a groove; 

 back black, with transverse yellow bands. 



Inhabits Brazils. 



The Black Yacare. Jacare nigra, Spix, Braz. t. 4. Natter- 

 er, Ann. Mus. Vien. i. 347, t. 21. Alligator Sclerops, var. Gray. 

 Syn. 62. 



Head ovate, triangular, depressed ; muzzle elongate, broad, 

 blunt ; frontal ridge very slightly sinuated, preorbital oblique, to 

 the edge of the jaw ; maxillary pits 3-3 ; upper eyelid striated ; 

 nuchal shields many, in 3 series; cervical in 5 series; dorsal acute- 

 ly keeled, the two lateral series higher, leaving a vertebral groove ; 

 black, with whitish spots, beneath white. 



Inhab. Brazils. Mus. Vienna. 



** Preorbital ridge indistinct or nom. Maxillary pits none. 



The Spotted Yacare. Jacare punctulatus, Spix, Braz. t. 2. 

 Alligator punctulatus, Dum. et Bib. E. G. iii. 91. Natterer, Ann. 

 Mus. Vien. i. 347, t. 25. 



Head triangular, oblong, rather gibbous, muzzle elongate, at- 

 tenuated, veiy flat, with a rounded point in front, a slight enlarge- 

 ment behind the nostrils; frontal ridge arched and slightly bent 

 back ; preorbital ridge none ; maxillary pits none ; upper part of 

 the eyelid rugose ; nape with 2 rows of plates ; back flat, without 

 any grooves or prominent keels, yellow, black-dotted ; sides with 

 some rows of larger scales ; olive, dotted and varied with black, 

 beneath yellowish. 



Inhab. Brazils. Mus. Vienna. 



Natterer's Yacare. Jacare vallifrons, Natterer, Ann. Mus. 

 Vien. i. 322, t. 24. 



Head triangular, oblong, rather gibbous; muzzle elongate, at- 

 tenuated, frontal ridge bent forwards, preorbital ridge none ; max- 

 illary pits none ; upper eyelid rugose ; nuchal shields many, in 2 

 series ; cervical obtusely keeled, in 5 bands ; dorsal obtusely keel- 

 ed ; olive, dotted coarsely with black, beneath yellowish. 



Inhab. Brazils. Mus. Vienna. 



g3 



