228 A CENTUEY OF SCIENCE 



curious group of armored placoderms, the remains of 

 which consist very largely of armor plates with little or 

 no traces of internal skeleton. There was also found in 

 association a shark, Cladoselache, of such marvelous 

 preservation that from some of the Newberry specimens 

 now in the American Museum of Natural History, New 

 York, Bashford Dean has demonstrated the histology of 

 muscle and visceral organs, in addition to the very com- 

 plete skeletal remains. 



Newberry 's work on these forms, begun in 1868, has 

 been carried to further completion by Bashford Dean and 

 his pupil L. Hussakof, as well as by C. R. Eastman. 

 Newberry 's other paleontological work was with the Car- 

 boniferous fishes of Ohio, the Carboniferous and Triassic 

 fishes of the region from Sante Fe to the Grand and 

 Green rivers, Colorado, and on the fishes and plants of 

 the Newark system of the Connecticut valley and New 

 Jersey. He also discussed certain mastodon and mam- 

 moth remains, and those of the peccary of Ohio, 

 Dicotyles. 



Joseph Leidy (1823-1891). 



We now come to a consideration of the work of Joseph 

 Leidy, one of the three great pioneers in American verte- 

 brate paleontology, for if we disregard the work of Hitch- 

 cock and others on the fossil footprints, few of the results 

 thus far obtained were based upon the fruits of organized 

 research. Leidy began his publication in 1847 and con- 

 tinued to issue papers and books from time to time until 

 the year 1892, having published no fewer than 219 paleon- 

 tological titles, and 553 all told. His earlier paleontolog- 

 ical researches were exclusively on the Mammalia, which 

 were then coming in from the newly discovered fossil 

 localities of the West. The discovery of these forms, 

 one of the most notable events in the history of our 

 science, will bear re-telling. 



The first announcement was made in 1847, when Hiram 

 A. Prout of St. Louis published in the Journal (3, 248- 

 250) the description of the maxillary bone of "Pal&o- 

 therium" (=Titanotherium proutii) from near White 

 River, Nebraska. This at once drew the attention of 

 geologists and paleontologists to the Bad Lands, or 



