2. THE SYSTEMATIC POSITION OF THE 

 TRILOBITES * 



As a preface to these remarks, it may be stated that there is 

 no intention of indulging in a controversy regarding trilobite 

 affinities. Professor Kingsley, as a biologist and authority on 

 living arthropods, naturally approaches the subject from a 

 standpoint nearly opposite to that of a trilobite investigator 

 or paleontologist. The differences of opinion or interpreta- 

 tion held by each are generally more appai-ent than real, and, 

 as stated, depend mainly upon the point of view. Further, 

 it cannot be expected that students of Lang, Glaus, and 

 Lankester will agree as to the value and significance of a 

 number of important characters, or upon certain theories 

 which have been the natural outcome of such differences. 



In the study of trilobite morphology and classification I 

 have made homologies and correlations from theories, opin- 

 ions, and observations which seemed most current and in 

 general favor in standard text-books. The chief purpose of 

 the investigation was to work out the structure and develop- 

 ment of the trilobite, and to apply the information to a classi- 

 fication of the members of the group itself. The results have 

 been recently published in the American Journal of Science 

 (February and March, 1897). No attempt was made to revise 

 the classification of the animal kingdom from the trilobite 

 standpoint, nor even to determine the branches of arthropod 

 phylogeny. The discussion of the systematic position of 

 Limulus was carefully avoided, though this is usually consid- 

 ered the chief end of any trilobite theorizing. The affinities 



* This paper was written to follow one by J. H. Kingsley, on " The Sys- 

 tematic Position of the Trilobites," published in the American Geologist, XX, 38- 

 40, 1897. 



