Dr. J. E. Gray on the Species of Alliyators. 329 



scutella elongate, in fourteen or sixteen longitudinal series. 

 Sides of the jaws pale, with five or six band-like spots ; the inner 

 pair of the first and second series of cervical scutella large and 

 equal-sized. 



Hab. Tropical America. 



This is very like the following ; but the head is rather broader, 

 and the dorsal and ventral shields are much larger and more 

 numerous. 



It is known from the young of Jacare nigra by its olive-colour, 

 the spots on the sides of the jaws, and the presence of the di- 

 stinct nuchal scutella. 



4. Jacare ocellata. 



Dorsal scutella broad, uniformly keeled, in eight longitudinal 

 series in the middle of the body ; ventral scutella in twelve lon- 

 gitudinal series, those of the hinder series smaller, longer, and 

 more numerous ; the central pair of cervical scutella in the first 

 series smaller than those that follow. 



Hab. Lake of Santa Cruz de la Sierra. 



** Face attenuated, rather high on the sides ; sides of the jaws one-coloured, 

 not spotted or banded. 



5. Jacare punchdata. 



Caiman (Jacaretinga) punctidatus, Spix, Bras. t. 2 (good). 

 Champsa sclerops, Natterer, Beitr. t. 22 (head, good). 

 Alligator punctidatus, Dura. & Bibr. Erp. Gen. ii. 91. 



Back pale yellow, brown-banded; the sides of the head yellow; 

 upper and lower jaws yellow, one-coloured, or minutely speckled ; 

 sides of the neck smooth, with flat scales. Nose rather high and 

 square. 



Hab. Brazils (Spite) ; Surinam ; Argentine Republic. 



Var. Sides of the neck rugose, with prominent keeled scales. 

 Dcmerara. 



Dr. Natterer figures two other species, under the names of 

 Champsa vallifrons (t. 23) and Ch. punctulatus (t. 24), the latter 

 of which seems to differ from the former in the head being 

 narrower and more tapering. I have seen no specimens agree- 

 ing with these figures ; but they look very like varieties of the 

 above. At the same time, some of our specimens appear to have 

 more attenuated snouts than others ; but when the callipers are 

 applied to the nose and to other parts of the head, the absolute 

 proportions of the parts are very nearly the same. 



I may observe that, characteristic as arc the figures of Dr. 

 Natterer' s paper, none of them exactly agree with our specimens 

 when measured. Perhaps this arises from their having been 

 drawn in perspective. 



In some specimens of this Jacare, the first and sometimes 



