342 Prof. Silliman^s Address before the 



enable us, in like manner, to restore their skeletons — when, with- 

 out doubt, they will be found to be appropriate companions of 

 the gigantic frogs of their day — not more acceptable however, 

 we may presume, in their regal sway, than were the storks, of 

 fabulous narrative, when appointed by Jupiter to reign over the 

 frogs of that epoch of comparative pigmies. We want nothing 

 but the fossilized bones of these primeval birds, to establish their 

 existence ages before the earliest period heretofore assigned to 

 them in the tertiary, or very recently in the Wealden, above the 

 oolite and below the chalk, by Dr. Mantell. 



The gigantic birds and frogs would be also in perfect keeping 

 with the colossal reptiles, the Ichthyosauri, Plesiosauri, Megalo- 

 sauri and Iguanodons of that middle reign, the fit successors of 

 the great Saurian fishes below the coal, as they were, in their 

 turn, successors or companions of the carnivorous cephalopods of 

 the Silurian rocks. 



DESIDERATA AND DIFFICULTIES. 



In speaking of the desiderata of American geology, I have only 

 to refer to the mention already made of the deficiencies in our 

 geological table. If those members of the geological series, in 

 which we are deficient, do really exist within our territories, 

 (giving them their widest range to the Pacific Ocean,) or, if they 

 exist even in any part of North America, it is most desirable 

 that they should be discovered, for our boundaries in science are 

 not limited by political divisions. There is much remaining yet 

 to be done in this country, and in all countries, even those that 

 have been most explored ; and the number of well instructed 

 geologists is now so considerable in all entightened communities, 

 that the great work will assuredly go forward with ceaseless 

 effort and with increasing success, presenting rich additions to 

 our knowledge and giving still greater precision and extension to 

 our scientific views. 



Geology has now survived most of its difficulties. To exam- 

 ine the structure of this earth is no longer regarded as a vain, 

 idle, or presumptuous pursuit. Its economical utility is admitted 

 by multitudes in our public counsels, who neither perceive nor 

 appreciate its high intellectual and moral interest, while the po- 

 lemical opposition is gradually yielding to the force of truth and 

 to more reasonable modes of criticism and interpretation. 



