156 Proceedings of the 



molluscs, the remains of which form a part of the marine deposits 

 known by the name of terrain secondaire, or Jurassic formations. 

 No feet of this animal have ever been found ; but in the cabinet at 

 Caen there is a block containing the imprint of the whole skeleton 

 of a stcneo-saurus, in which is observed the form of the first joint of 

 the hind feet, which resembles that of the ikan dugung. It appears 

 that there was but one middle toe, of a length beyond all proportion, 

 accompanied by the rudiments of a lateral joint, thus, in some re- 

 spects, resembling the horse, but as well adapted for swimming as 

 the horse's hoof is for walking. M. St. Hilaire, however, thinks it 

 probable that the feet of the teleo-saurus were different from those of 

 the steneo-saurus, inasmuch as there certainly existed great difference 

 in the other parts of the organization. Thus the nostrils of the 

 former are entirely terminal, giving the idea that the muzzle termi- 

 nated in a sort of snout, while those of the latter are open at the 

 top, nearly in the same manner as those of the gavials. The teeth 

 also of the steneo-saurus resemble those of the gavial, while those 

 of the teleo-saurus are thin, and spring laterally ; hence it may be 

 supposed that the former preyed on living animals, while the latter 

 lived on submarine vegetables and algae : indeed, from the granite 

 stones found in the midst of the fossil bones, M. St. Hilaire was 

 inclined to believe that the animal swallowed stones, for the purpose 

 of bruising and facilitating the digestion of the herbs and grains. 

 From these examinations M. St. Hilaire deduces a theory, that there 

 have been three epochs of animal creation. In the first, (to which 

 belongs the teleo-saurus,) animals, without lungs, existed alone ; in 

 the second, animals with pulmonary organs began to appear ; arid 

 in the third, which comprehends the present world, the earth was 

 covered with animals of a species of which no analogous fossil re- 

 mains have been discovered. It results from this theory, that man 

 is of a very modern origin as compared with the age of the globe. 



Bicephalous Lizard. On the 9th of May, M. Beltrami commu- 

 nicated some curious particulars relative to the two-headed lizard men- 

 tioned in our last Number (page 570), which lived five months in the 

 possession of M. Rigal, an apothecary at Argelles. It used its two 

 heads simultaneously for eating when it could seize its food as it 

 liked. If a single insect were presented to it, both heads attempted 

 to seize it, and the one which failed endeavoured to snatch it from 

 the other. When, however, one head was satiated, the other refused 

 food, but if water were offered, the head which had not eaten would 

 drink for the other, which then, in its turn, refused to drink when its 

 companion was satisfied. The animal has five feet, four of which, 

 placed in the usual position, served it for locomotion ; the fifth is 

 situated at the point of junction of the two necks, at the upper part 

 of the common body. It has nine distinct toes, evidently resulting 

 from the union of the two fore-feet. This foot, or paw, served it to 

 clean itself, and to carry the food alternately to the two mouths ; and 



