1911] Teller, Fossils from the Palwozoic Formations. 179 



first publication, as in the early days of the science of palaeon- 

 tology very many descriptions of new species were made without 

 illustrations of any kind. 



To the specialist and student types are now the most valuable 

 portion of any collection and are always guarded with the utmost 

 care. They are usually marked in some conspicuous manner, 

 usually with a small rhomb or star of enameled paper securely 

 gunned to each specimen, each describer selecting such form and 

 color as may be most pleasing to himself and which is recognized 

 as his private mark. 



A specimen may be both a generic and a specific type, this is 

 always the case where the specimen is the one first used in found- 

 ing a new genus and it must therefore also be the first of a new 

 species ; in many instances there are also other individuals in the 

 type series than those that have been figured but have been used 

 in assisting in the description of the genera or species and must 

 therefore become a part of the types. 



Type specimens now constitute the most important material 

 in museums of natural history. The true appreciation of this 

 fact has become general in recent years as shown in the lately 

 published catalogues of the types possessed by different museums ; 

 the most of these publications have been issued in America and 

 England. 



This valuation of type material has also come through the 

 work of specialists in their efforts to monograph groups of organ- 

 isms as it is upon the type material that the true value of natural 

 history for this purpose depends ; therefore it is of the greatest 

 importance and value to learn the whereabouts of types. 



For the purpose of this paper we have confined ourselves to 

 the term type as being the proper one for our use and in all cases 

 have confined our research to the original description of species 

 following up all cross references. 



