OF EECENT CEOCODILIANS. 163 



Alligator niger, Owen, Cat. Osteol. Spec. Mus. Coll. Surg. p. 704. n. 166 (adult). 

 Jacare nigra, Gray, Cat. Tort. & Croc. 65 ; Ann. & Mag. N. H. x. 328, 1862. 



Hab. Para, 13 feet long (Graham); Guiana (Owen). 



I think it better to adopt Spix's name, as sclerous has been used for all the species. 



B. Head short; orbits with diverging ribs in front to edge of.jaiv. Dorsal scutella 

 broad, slightly keeled, equal; the lumbar scutella in four longitudinal series. 

 Nuchal scutella distinct, in two cross series. Eyelids rugose, with a small internal 

 bone. Back olive, banded with broion. Cynosuchus, Gray, Ann. & Mag. N. H. x. 328. 



In many of the specimens the first scale of the nuchal shield has two keels, in others 

 it has only one ; but in several specimens the scale has two keels on one side and only 

 one on the other. 



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. Jacake latieosteis. (Dog-headed Jacare.) 



Dorsal shields in eight longitudinal series, four on each side. Ventral shields in 

 twelve series. 



Crocodilus latirostris and C. yacare, Daud. Kept. ii. 407, 417. 



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



Champsa fissipes, \Yagner, Icon. t. 17. Natterer, Beitr. t. 22 (good). 



Crocodilus sclerops, Wied. Abbild. t. Blainv. Osteogr. Crocod. t. 3. f. 2, t. 4. f. 13. Schinz, Rept. 



t. 112. 

 Jacare fissipes, Gray, Cat. Tortoises B. M. 64. 

 Alligator sclerops, Pr. Max. Abbild. t. 

 Alligator cynocephalus, Dum. & Bib. Erp. Gen. ii. 86. 

 Jacare latirostris. Gray, Ann. & Mag. N. H. x. 328. 



Hab. Brazils ; Pernambuco (J. P. G. Smith) ; Surinam. 



The nose of the young specimen is as long as the width at the eighth tooth. The 

 nose from the ridges nearly as long as the back of the head ; width of the muzzle at 

 the notch one-half the length of the head. 



Var. 1 (three young, in spirit). Head short; side of face pale, with a dark ispot 

 under each ear, and another larger under each eye. The lower jaw pale, five round 

 spots on each side, tlie middle one, under the eyes, the largest. Back black, witli inter- 

 rupted or iiTegular pale brown cross bars. 



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



The smaller specimen is peculiar for the very small size of the ventral sliield in front 



