180 Bulletin Wisconsin National History Society. [Vol. 9, No. 4. 



IV. MATERIAL AND METHOD. 



Something over twenty years ago for our own use and infor- 

 mation we started a card catalogue of the species of fossils that 

 have been described from the palaeozoic rocks of Wisconsin. 

 When we came across the description of a species that we knew 

 or had reason to believe was from the formations of this state, we 

 made a card of it, by whom it was described, the formation from 

 which it was collected, the publication in which it was described, 

 and if there was no figure of the species in such case we referred 

 as a second reference to that work in which the next description 

 of the species was to be found if accompanied by a figure, and if 

 that work should be one not readily accessible to the student or 

 collector as a third reference to that work in which the Wisconsin 

 collector will find a description and figure of the species ; next the 

 locality from which the type was collected, and finally the institu- 

 tion or collection in which the type was deposited. 



As many of the earlier publications in which the descriptions 

 were given contained no figures whatever and in many cases no 

 definite locality was given, the work was necessarily slow. Many 

 cards were made that had to be eliminated and some of these 

 finally had to be replaced. Synonyms crept in and had to be care- 

 fully guarded against. The most difficult work was to find the 

 location of the types ; those that were in the larger institutions 

 were placed after years of work, the publication of the list of the 

 types in the American Museum of Natural History being the most 

 important aid received ; as a rule we found that other scientific 

 institutions, colleges, and private collections had no lists whatever, 

 and even in some cases were not aware that they had any such 

 valuable material in their collections until advised of the same. 

 Our research has been very exhaustive. The number of geological 

 works we have reviewed we would not undertake to enumerate. 



