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careful examination of the rocks of his region he had discovered 

 those "platforms of death" as he well named those crowded 

 masses of remains of fossil fishes which he found in the thin 

 strata of the lower Archimedes limestone. One specimen found 

 by him in this prolific locality proved to Prof. Agassiz that he 

 was correct in his conclusions already drawn from comparative 

 anatomy, and he stated that it enabled him as upon an estab- 

 lished basis of fact (not reasoning) to take up his studies of 

 fossil fishes anew and pursue them further than ever, and he 

 had portions of this collection long in his possession. This 

 minute and careful personal examination and observation of 

 the different strata and abundant collection of specimens re- 

 dounded greatly to the advantage of his collection which con- 

 sequently contains a greater number of what may be called 

 type-specimens than any other collection. From it were selected 

 almost wholly the specimens with which to illustrate the re- 

 ports upon Paleontology of Iowa and the same is largely true 

 also of the volumes of the Illinois reports. He had also during 

 these years gathered together a scientific library of great value. 

 The writer well remembers how he exercised a severe economy 

 in other directions to enable himself to purchase the rare and 

 expensive books needed for his studies in his favorite field. 

 Wherever a book was to be had in exchange for specimens it 

 was obtained regardless of expense in the way of payment for 

 it, and where money was required it was freely expended. Thus 

 well equipped, both by personal experience in the field, and by 

 the study of actual specimens as well as of books, he came to 

 his life work of which it is enough to say that it has been done 

 with characteristic thoroughness and fidelity, and reported with 

 an ability and minuteness that have made his reports text 

 books of the Palaeontology of Illinois, and a monument of his 

 own industry and ability. Professor Worthen like General 

 Grant, never withheld the meed of praise and credit from his 

 assistants and co-laborers. He had the countenance, support 

 and friendly aid of numerous lovers of science in all parts of 

 the State. He also secured for the work the aid and assistance 

 of the ablest specialists of the day in every department, notably 

 Prof. J. D. Whitney in mineralogy, Prof. Leo Lesquereux in 

 coal measures and coal plants, Profs. F. B. Meek, Orestes St. 

 John, Dr. John S. Newberry and Mr. E. O. Ulrich in different 



