288 PALEONTOLOGY OF ILLINOIS. 



exception, relied upon these delusive external characters in dis- 

 tinguishing their species, and the result is that it is now almost 

 impossible to identify a large number of forms which they have 

 described and named. Their names have become current, but 

 we have no assurance that we are really dealing with the forms 

 to which the names were originally applied. Frequently, too, 

 the names have been applied by subsequent observers to totally 

 different organisms, so that no little amount of confusion has 

 resulted. The ill effects of this state of things upon stratigraph- 

 ical geology, can scarcely be exaggerated, since it is often quite 

 impossible to be sure of the identification by various authors 

 of the characteristic fossils of particular horizons. Thus, one 

 often finds Chsetetes lycoperdon Say, Stenopora fihrosa Gold- 

 fuss, S. columnaris Geinitz, and Monticulipora or Chsetetes petro- 

 politanus Pander, quoted in lists as typical fossils of certain 

 stratigraphical horizons; but it is safe to say, that in almost 

 every instance there is no surety that the indentification of the 

 species rests upon anything beyond the worthless characters of 

 external form and general composition. 



This confusion will continue so long as such illy characterized 

 and unidentifiable species are recognized by palaeontologists. 



Some indulgences might be extended to early authors but I 

 hold that there is absolutely no excuse whatever for such work 

 at the present time when our facilities for giving our work 

 a permanent value, by doing it well, are so much better than 

 they were in former years. Of greater value, at present, than 

 the mere addition of new species to our lists, is the proper elu- 

 cidation of those already named. 



Until within the last ten years the Palaeozoic Bryozoa did not 

 receive the attention from palaeontologists that they deserve, 

 and previous to 1875, Dr. Hiram A. Prout was the only Ameri- 

 can author who aimed to introduce some system into their 

 classification. Unfortunately, his labors were almost exclusively 

 confined to the Bryozoa of the Carboniferous rocks, and consist 

 mainly of careful delineation of species and genera. On account 

 of his limited acquaintance with the Silurian, Devonian and 

 Mesozoic forms, his conclusions were often faulty. However, 

 when we consider the time and the primitive methods of inves- 

 tigation then employed, we are forced to credit him with fine 



