viii PKEFACE. 



former, the Plants and Fishes by the latter. Both these firms deserve 

 our sincere thanks, not only for the good quality of their work, but for 

 the courtesy and patience with which they co-operated in all efforts to 

 secure a creditable result. 



The Amphibians offered peculiar difficulties to the lithographers. 

 They were drawn on stone directly from the fossils, and as the color of 

 these were jet black, like the matrix, and their forms were discernible 

 only by a practiced eye, the fair degree of success attained in their de- 

 lineation deserves special praise. 



J. S. N. 



