EARLIEST REPTILES. 67 



combining the fish and reptile in the most unequi- 

 vocal manner. Despising, however, the great fact 

 which shines through these obscurities, this per- 

 son, and I am sorry to add, geologists generally, 

 can only fasten upon such particulars as may be 

 made out to be difficulties in the way of generali- 

 zation. Passing to the particulars, a few land 

 lacertilians come first, whereas the first, according 

 to my hypothesis, ought to be marine forms, and 

 linked to fish. He says of this difficulty, that I 

 have stated it feebly. Perhaps it would have been 

 well for his own credit that he had stated it some- 

 what less confidently ; for before his sheets had 

 seen the hght, a prospect had arisen of his affir- 

 mations on this point being thoroughly falsified. 

 In Silliman's Journal, for April 1845, is an account 

 of sandstone surfaces pretty far down in the Car- 

 boniferous formatio7i of Pensylvania, marked with 

 the vestiges of terrestrial animals. Setting aside 

 in the meantime one class of these markings, 

 which are said to indicate wading birds, we have 

 a variety of others plainly denoting reptiles. In 

 one group, the foot consists of a ball, with five 

 toes radiating from it in fi-ont. In another, the 

 impression resembles that made by a coarse 



