384 S. WELLER FOSSILS AS AID IN TEACHING STRATIGRAPHY 



in the two volumes constituting Bulletin 92 of the United States Na- 

 tional Museum, in which no less than 1,342 pages are devoted to a biblio- 

 graphic index alone of the known Ordovician and Silurian fossils in 

 America. No tabulation of the actual number of genera and species rec- 

 ognized in these volumes is given, but there are probably somewhere near 

 8,000 species recorded. More than twenty years ago a list of 3,754 species 

 of American Carboniferous invertebrate fossils were recorded,^ and this 

 list could be much amplified at this time. Probably 20,000 American 

 Paleozoic fossils have been described and named, with the descriptions 

 scattered through a body of literature to be found in hundreds of volumes. 

 With the Mesozoic and Cenozoic forms added to these, the number sug- 

 gested above would be very greatly increased, though probably not 

 doubled. 



The actual task of one who is by profession an applied paleontologist 

 is not unlike, in many ways, the work of a student of the literature of an 

 unknown and forgotten language and a language that has been recorded 

 by word symbols rather than by a phonetic alphabet. The fossil species 

 constitute the symbols in this literature and their association in faunules 

 and faunas are the sentences and paragraphs. The literature as a whole 

 is one great record of a continuous history, but the pages in this record 

 are not assembled in regular order, as they might be in a volume in a 

 library, but are scattered over the whole world ; some of them are fairly 

 complete, but many are mere scraps and fragments, while others have 

 been lost beyond recovery or have not yet been found.- The assembling 

 and piecing together of this great historical work and the translating of 

 the history so recorded into our written or spoken language are no small 

 task. Furthermore, the bringing together of this paleontologic record is 

 still far from complete. Pages of the record here and there, belonging 

 to many different chapters, have been read in a more or less satisfactory 

 manner, but new information, which is being constantly accumulated, 

 makes necessary the re-reading of many of the pages already deciphered. 



The teacher who seeks to arouse a thoroughgoing interest in the sub- 

 ject of applied paleontology has a most difficult task. He labors at a dis- 

 advantage in teaching a subject that is in the making,- and although this 

 very fact may lend vast interest to the work when the student has pro- 

 gressed far enough to appreciate the possibilities for original research, 

 it makes it far more difficult to present to beginners. It is highly de- 

 sirable that the student should become familiar with as large a number 

 as possible of fossil genera and species, which are the words of the lan- 



2 Stuart Weller: Bull. U. S. Geol. Survey, No. 153, 1898. 



