JAMES DWIGHT DANA 245 



of Naumann. In the sixth edition (edited by E. S. Dana), the 

 system of Miller is followed, though the symbols of J. D. Dana 

 adapted to the system of Naumann are also given. 



The fact is worthy of incidental mention that J. D. Dana con- 

 structed a series of glass models of crystals as early as 1835 

 probably the first models of this kind. 



The fifth edition of the System of Mineralogy is a monumental 

 work in the thoroughness with which the literature of the science 

 was ransacked to give completeness and accuracy to the synonymy. 

 The changes made in the successive editions have kept pace with 

 the progress of science ; and the book still stands, as it stood more 

 than seventy years ago, at the head of the encyclopedic treatises 

 on descriptive mineralogy. 



Dana's reputation as a zoologist rests chiefly upon the Reports 

 on the Zoophytes, and on the Crustacea, of the United States 

 Exploring Expedition. Each of these great works is illustrated 

 with a magnificent folio atlas, many of the figures being colored. 

 All the figures of Crustacea and most of those of Zoophytes are 

 from Dana's own drawings. More than two hundred new species 

 of coral animals, and more than five hundred new species of 

 Crustacea, are described. Besides the vast amount of detail work 

 represented by the description of so many new species, these 

 reports contributed to the progress of science by the advanced 

 views on classification which they presented. 



The Report on Zoophytes especially was an epoch-making work 

 in that department of science. The number of known species of 

 coral animals was almost doubled by Dana's collections. More- 

 over, most of the species previously described had been based on 

 the skeleton (coral) alone, few naturalists having had any oppor- 

 tunity to see the creatures alive or to study their soft parts. Nat- 

 urally, therefore, the relations of the known species were but 

 imperfectly understood. Dana's report, accordingly, did not con- 

 fine itself to the species collected in the expedition, but included 

 all species then known. It was thus a monograph of the entire 

 group. The number of species of the coral animals recognized 



