Genus 2. Caiman.
Dental formula 20-20/22-22 (Natterer). The face is without median or transverse ridges, but it is sharply angulated along a line which extends from the orbit forwards along the sides of the snout. The anterior nasal aperture is undivided in the dry skull. The vomers do not appear in the palate. The supra-temporal fossæ are obliterated, the circumjacent bones uniting over them. The webs of the feet are rudimentary. The dorsal scutes are articulated together by lateral sutures and anterior and posterior facets; and there is a ventral shield, consisting of similarly articulated scutes.
Natterer[1] has described three species of Caiman—C. palpebrosus, C. trigonatus, and C. gibbiceps. The Caimans abound chiefly in tropical South America; but they are found as far north as Mexico, a specimen of C. palpebrosus in Dr. Grant's collection coming from that country.