OF RECENT CROCODILIANS. 167 
to this animal that Cuvier considered Adanson’s West-African specimen a variety of 
this species. 
Duméril & Bibron evidently considered the African and the American animals 
the same species; and we a short time ago received from M. Braconier, of the Jardin 
des Plantes, a skeleton of the African species under the name of Alligator palpe- 
brosus, var. 
A. Head shelving on the sides. Nuchal scutella in a single cross series, cervical scutella 
jive pairs; dorsal scutella highly keeled, irregular, in six series; the lumbar 
scutella in two longitudinal series; the gular and two outer lateral series of 
ventral scutella keeled. The flat upper disk at the base of tail broad and strongly 
crested. Paleosuchus, Gray, Ann. & Mag. N. H. x. 330. 
1. Caiman Trigonatus. (Rough-backed Alligator.) 
Crocodilus trigonatus, Schn. Amph. 161. 6. Tiedemann, Amph. 66, t. 67. 
Crocodilus palpebrosus, var. 2, Cuvier, Oss. Foss. y. 40, t. 2. f. 1. 
Caiman trigonatus, Gray, Cat. Tortoises &c. B. M. 66; Ann. & Mag. N. H. x. 330, 1862. 
Alligator palpebrosus, Brithl, Skel. Krok. t. 19. f. 3. 
Champsa trigonata, Natterer, Beitr. t. 26 (good). 
Hab. '‘Tyopical America. 
The largest specimen in the British Museum is rather above 4 feet long. The young 
specimens have the lateral ventral shields keeled. 
B. Head flat, and erect on the sides. Nuchal scutella many, in two cross series ; 
cervical scutella three pairs; dorsal scutella slightly keeled; the lumbar 
scutella in four longitudinal series; the gular, the ventral, and the lateral 
abdominal scutella keeled. The flat upper disk at the base of the tail elongate. 
Aromosuchus, Gray, Ann. & Mag. N. H. x. 330. 
2. CAIMAN PALPEBROSUS. (Banded Alligator.) 
Brown ; tail black-banded. 
Crocodilus palpebrosus, var., Cuvier, Oss. Foss. v. t. 1. f. 6-17 and t. 2. f. 2. 
Champsa palpebrosa, Natterer, Beitr. t. 27 (good). 
Caiman (Jacaretinga) moschifer, Spix, Bras. t. 1 (skull). 
Caiman palpebrosus, Gray, Cat. Tortoises &c. B. M. 67; Ann. & Mag. Nat. Hist. x. 330, 1862. 
Crocodilus palpebrosus, Tiedem. Nat. Amph. t. 6. 
Alligator palpebrosus, Merrem, Syst. 35. Gray’s Syn. Rept. 63. 
Hab. Tropical America. 
Natterer figures the head of a species under the name of C. gibbiceps; but I deh not 
see how it differs from the above, except that the head is a little higher—perhaps a 
sexual distinction.- Dr. Strauch regards C. gibbiceps as the same as C. palpebrosus. 
2a2 
