328 Dr. J. E. Gray on the Species of Alligators* 



1. Jacare. 



Head moderately higb, shelving on the sides. Orbits united 

 by a distinct bony cross ridge. Eyelids striated or rugose, 

 strengthened by a small internal bone. The cervical scutella 

 four or five pairs, forming a shield ; the dorsal and ventral scu- 

 tella bony, articulated together, forming a dorsal and ventral 

 shield ; the gular and ventral scutella smooth. 



A. Head elongate j interorbital ridges strong. Dorsal scutella elongate, 

 keeled, keels of vertebral series highest ; lumbar scutella in six longitu- 

 dinal series. Nuchal scutella small, compressed. Eyelids striated, with 

 a rather large internal bone. Back black, yellow-varied. Melanosuclius. 



1. Jacare nigra (Black Jacare). 



Crocodilus sclerops, Schii. Ampli. 162; Cuvicr, Arch. Zool. ii. t. 2. f. 3. 



Crocodilus Yakare, Daud. Rept. ii. 414. 



Alligator Sclerops, Cuvier, Oss. Foss. v. 35, t. 1. f. 7 & 16, t. 2. f. 3. 



Caiman niger, Spix, Bras. t. 4 (good). 



Champse niger, Natterer, Beitr. t. 21 (good). 



Hab, Para; 13 feet long [Graham), 



I think it better to adopt Spix's name, as sclerops has been 

 used for all the species. 



B. Head short : orbits with diverging ribs in front to edge of jaws. Dorsal 

 scutella broad, slightly keeled, equal j the lumbar scutella in four longi~ 

 tudinal series. Nuchal scutella distinct, in two cross series. Eyelids 

 rugose, with a small internal bone. Back olive, brown-banded. Cyno- 

 suchus. 



a. Head short, broad, depressed, with very distinct preorbital ridges to the 

 edge of the jaw. Cervical disk short, broad, formed of four bands of 

 scutella. Sides of jaws pale, with a series of dark spots, 



2. Jacare latirostris. 



Crocodilus latirostris, Daud. Rept. ii. 417. 



Caiman fissipes, Spix, Bras. t. 3 (good). 



Champse fissipcs, Wagner, Icon. 1. 17 ; Natterer, Beitr. t. 22 (good). 



Alligator sclerops, Pr. Max. Abbild. t. 



A. cynocephalus, Dum. & Bibr. Erp. Gen. 86. 



Hah, Brazils. Pernambuco (/. P. G. Smith). 



The nose of the young specimen is as long as the width at 

 the eighth tooth. 



b. Head elongate, longer than the width at the eighth tooth, with none or only 

 indistinct evanescent ridges from the front of the orbit. Cervical disk 

 oblong, elongate, of five series of scutella. 



* Face depressed, broad; sides of the jaws with a series rf large coloured 

 spots, as in the former section. 



3. Jacare lohgiscutata. 



Dorsal scutella elongate, longer than broad, uniformly keeled, 

 in ten longitudinal series in the middle of the body; ventral 



