Doubtless on the whole the habits of the phytosaurs were not very unlike those of the modern gavials, which they so strongly resemble in form, size, and general characters. But they differ very greatly from the gavials in the extreme posterior position of the nostrils, and in the greatly elongated teeth of the front end of the beak, teeth which must have had some especial and peculiar use. Nor is the position of the nares to be accounted for satisfactorily by reference to aquatic habits. It has been suggested that the creatures used the very long and slender beak in prodding and probing in the sand and mud for soft-bodied invertebrates, worms and the like, for which the teeth would be especially fitted; and that the posterior position of the nostrils may be in part, perhaps wholly, accounted for by this habit, which permitted the reptiles to breathe without extricating the beak from the mud or shallow waters. That the animals were wholly and intensely carnivorous in habit is attested by their teeth; although they are called “plant saurians,” they never had anything to do with plants in the way of food. Unfortunately so far no specimens have ever been found showing the remains of stomach contents, nor have any been found showing impressions of the form of the body or of any of its parts. Until such specimens are found, as they doubtless will be eventually, one can be less sure of the precise details in their life reconstructions. However, the skeleton is now known nearly completely, and this suffices to give a very approximately correct idea of what the animals were like when alive. CHAPTER XV CROCODILIA The order of reptiles to which the name Crocodilia is technically applied comprises less than twenty-five living species, popularly known as crocodiles, alligators, caimans, and gavials. They are often of great size, ugly and repulsive in appearance, cruel and vicious in habit, wholly carnivorous, and denizens, almost exclusively, of fresh-water lakes or rivers in tropical and subtropical regions; a few only venture into the sea near the shores. They are all excellent and powerful swimmers, but are by no means exclusively aquatic in habit, many of them spending a large part of the time on the shores; and they invariably seek the land for the deposition and hatching of their eggs. In size they are the largest of living reptiles, some of the existing species reaching a length of twenty-five feet, while some extinct species were probably fully twice that length.