162 DR. J. E. GEAT'S SYNOPSIS OF THE SPECIES ' 



II. The ventral scutella thin, the dorsal scutella bony, not articulated together. The 

 eyelids fleshy, smooth. The cervical scutella in pairs, separate. Nasal hone 

 elongate, separating the nostrils. North America. 



3. Alligator. The face broad, depressed. 



Section I. The ventral scutella like the dorsal ones, bony and articulated together, 

 forming a shield. The eyelids ivith an internal bony plate. The cervical scutella 

 in pairs, forming an elongated shield. Nasal bone short. Tropical America. 



1. Jacabe. 



Head moderately high, 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 scutella 

 both consolidated together, forming a dorsal and ventral shield ; the gular and ventral 

 scutella smooth. 

 .7aca)-e,Gray,Cat.Tort.Croc.&c. B.M.64,1844; Ann. & Mag. N.H. 3rd series, x. 327, 1862. Huxley, 



Proc. Linn. Sec. 1859, 4. 

 .Tacaretinga, Spix, Lacert. 



The pits in the maxilla are the cavities left by the preorbital ridges as they advance. 

 The intermaxillary bone short, truncated behind, with an elongate-oval or lanceolate 

 cavity between this and the front of the palate. 



The figures of Natterer are excellent to general appearance, but they do not agree 

 with the measurements of our specimen; that is to say, the nose of Champsa fssipes, 

 from the ridge, is about the same length as the forehead, but in his figure it is 

 represented as larger, and it is so in all the other figures : perhaps this is to allow for 

 the perspective. 



A. Head elongate ; interorbital ridges strong. Dorsal scutella elongate, keeled, keels of 

 vertebral series highest ; lumbar scutella in six longitudinal series. Nuchal scutella 

 small, compressed. Eyelids striated, with a rather large internal bone. Back 

 black varied with yellow. Melanosuchus, Gray, Ann. & Mag. N. H. x. 328. 



1. Jacaee nigea. (Black Jacare.) 



Crocodilus sclerops, Schn. Amph. 162. Blainv. Osteogr. Crocod. t. 3. f. 2, t. 4. f. 13. 



Crocodilus yakare, Daud. 



Alligator sclerops, Cuvier, Oss. Foss. v. 35, t. 1. f. 6 & 7, t. 2. f. 3. Briihl, Skelet. Krokod. t. 12. 



f. 3, 5, 6, 7, t. 19. f. 21. 

 Alligator sclerops, var., Gray, Syn. Rept. 

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

 Champsa nigra, Natterer, Beitr. t. 21 (good). 



