OF RECENT CROCODILIANS, 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 sc/erops has been used for all the species. 
B. Head short; orbits with diverging ribs in front to edge of. jaw. 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 brown. 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. JACARE LATIROSTRIS. (Dog-headed Jacaré.) 
Dorsal shields in eight longitudinal series, four on each side. Ventral shields in 
twelve series. 
Crocodilus latirostris and C. yacare, Daud. Rept. ii. 407, 417. 
Caiman fissipes, Spix, Bras. t. 3 (good). 
Champsa fissipes, Wagner, Icon. t. 17. Natterer, Beitr. t. 22 (good). 
Crocodilus sclerops, Wied. Abbild. t. Blainy. Ostéogr. 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. Gén. 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 spot 
under each ear, and another larger under each eye. The lower jaw pale, five round 
spots on each side, the middle one, under the eyes, the largest. Back black, with inter- 
rupted or irregular pale brown cross bars. 
Hab. Pernambuco (J. P. G. Smith). 
The smaller specimen is peculiar for the very small size of the ventral shield in front 
