•J\)-J CKOC'OUII.ID.K. 



Si/no^isis of the S^ja ies. 



I. Ui)per eyelid incompletely bony ; supratemporal fosste present ; 

 iive teeth in each praeniaxilla ; 17 to 20 mandibular teeth on 

 each side. 



A. Orbit produced anteriorly to the ver- 



tical of the ninth or tenth maxillary 

 tooth ; upper eyelid flat ; vomer 

 exposed on the palate 1. nir/er, p. 292. 



B. Orbit not produced anteriorly; upper eyelid rugose, more or 



less distinctly raised into a small horn. 



The width of the snout, on a line with the 



anterior borders of the orbits, equals its 



length ; three or four transverse rows of 



large nuchals, only one of which is com- 

 posed of four scutes 2. latirustris, p. 293. 



Snout longer than wide at the base ; four 



or five transverse rows of large nuchals ; 



all the scutes on the body, limbs, and tail 



bony in the adult ' 3. sclerops, p. 294. 



II. Upper eyelid entirely bony ; supratemporal fossse obliterated ; 

 four teeth in each proemaxiUa ; 20 to 22 mandibular teeth on 

 each side. 



Rome or all of the scutes between the hind 



limbs in two or three longitudinal series ; 



caudal cres-t double up to the ninth or 



tenth verticil inclusively . . 4. trlgonatus, p. 2'JG. 



All the shields between the hind limbs in 



four series ; caudal crest double up to the 



eleventh or twelfth verticil inclusively. . 5. palpehrosus, p. 296. 



1 . Caiman niger. 



Caiman niger, Spix, Laceii. Bras, p. 'A, pi. iv. (1825). 



Champia nigra, Jf'm/ler, /Si/st. Amph. pi. vii. tig. 1 (18o0j ; yatterer, 



Ann. Wien. Mus!\\. p. 320, pi. xxi. (18J0). 

 Jacare nipra, Gray, Cat. Tort. L^r. p. (v) (18-14), aiul Tr. Zoo/. Soc. 



vi. p. 162 (1867), a77d Cat. SJi. liept. n. p. -.'o (1872). 



ttssipes ?, Hiixlejf, Journ. Linn. Soc. iv. p. 4 (1860). 



Alligator niger, Strauch, S;/n. Crocod. pp. 17 i!v: 71 (186()). 



18 (or 19) upper and 17 or IS lower teeth on each side: fourth 

 maxillary tooth much longer than the third. Head once and three 

 fifths to once and two thirds as long as broad ; snout moderate, 

 obtuse, a little longer than broad ; a feeble transverse ridge in fiont 

 of tlie concave interorbital region, bordering two deep concavities ; 

 two oblique ridges on each side of the snout, one from the orbit to 



