From the general structure of their bony framework it is difficult for Crocodiles to turn round or move otherwise than forward. This circumstance renders it easy to escape their pursuit. When chased by a Crocodile, it can be avoided by describing a circle, or running in a succession of curves. Upon the banks of the Lake of Nicaragua, in America, an Englishman was once pursued by an Alligator which had surprised him when on its margin. The animal was gaining upon him rapidly, when some Spaniards who witnessed the scene cried out to him to run round it. Thus fortunately warned the pursued dodged the Alligator, and escaped from his dangerous enemy (Fig. 33). [Illustration: Fig. 33.--The Englishman and the Caiman, or the Circular Flight.] [No specimens of the _Crocodilidæ_ have been found in Europe, and until very recently none had been found in Australia, but they are very common in the new colony of Queensland, an Alligator twenty feet long having been shot on the banks of the Mackenzie river, which was afterwards exhibited at Rockhampton. Crocodiles, properly so called, are found in Africa, Asia, and America. The Gavials seem to be limited to the Ganges and other large rivers in India. Besides the Gavial, Asia produces three other species, namely, _C. vulgaris_, _C. galeatus_, and _C. bifurcatus_. Of the first, Siam is the chief locality; the others are found in the rivers which debouch into the Indian Ocean and the Ganges. THE ALLIGATORIDÆ Include the _Jacares_, _Alligators_, and _Caimans_. The _Jacares_ have the head oblong and depressed, with a ridge across the face in front of the eyes; teeth unequal, canines of the lower jaw fitting into a pit in the upper jaw; toes only partially webbed, eyelids fleshy, nostrils separated by a cartilage. Five species are described--namely, _J. fissipes_, from Tropical America, six feet in length; _J. sclerops_, from the Brazils; _J. Nigra_, also from the Brazils; _J. punctulatus_, with triangular oblong head, muzzle elongated, thin and flat, with a rounded point in front, and a slight enlargement behind the nostrils; _J. vallefrons_, differing slightly from the above--both natives of the Brazils. _Alligators_ have the jaws oblong, much depressed, broad and nearly parallel; forehead with a small longitudinal ridge between the orbits; feet fringed, toes half webbed, the outer toes free; nostrils separated by a bony septum rising from the upper edge, muzzle lengthening with age. One species only is known, which is a native of North America; it attains a length of six to seven feet, and is known also as _Crocodilus Mississipensis_. The _Caimans_ have the jaws oblong, depressed, rounded, and swollen at the end, without frontal ridges or maxillary pits; teeth unequal, the lower canines fitting into pits in the upper jaw; toes webbed. There are three species described--_C. trigonatus_, _C. palpebrosus_, and _C. goddeceps_, all natives of Tropical America.