158 section b. vertebrata. 



The Value of Type Specimens and Importance of their 

 Preservation. By Professor O. C. Marsh. 



In the present state of Natural Science, there are too many 

 obstacles in the path of the original investigator. That this is 

 the case in the study of Botany, we may well believe, as authorities 

 of that Science have frequently placed the fact on record. It is 

 certainly true that everyone who does original work in systematic 

 Zoology, either among the living or extinct forms, meets many 

 difficulties at the start in endeavouring to ascertain what others 

 have done before him. The literature of the subject is often dis- 

 couraging from its extent, and especially from its uncertainty. If 

 the work in hand requires the comparison of type specimens, the 

 difficulties greatly increase, and often prevent definite conclusions. 

 The t}'pe will frequently be found the most important element in 

 the problem, far more so than the literature, however extensive. 

 This is more especially true among the extinct vertebrates, with 

 which the present communication mainly deals. 



(i) The Vahie of Type Specimens, 



The value of a type depends first of all upon whether it is a charac- 

 teristic specimen, worthy of being the representative of a new group 

 of individuals. Without this distinctive quality, its importance is 

 greatly diminished. If, for example, the specimen first described 

 is immature, its essential features may thus be obscured, and its 

 value as a type much diminished. On the other hand, a very old 

 animal may be uncharacteristic. The teeth of a mammal, for 

 instance, may be worn down or even lost, so as to make the normal 

 dentition uncertain. This is true of recent forms, but is more 

 important if the type belongs to an extinct fauna, as then the 

 chance of duplicating it is much less. 



The value of a type specimen again may depend largely upon 

 its completeness. Among the invertebrates, especially those now 

 living, types are usually complete enough to shew the more im- 

 portant features. This, however, is far from being the case among 

 extinct forms, particularly from the older formations, and the 

 records of Paleontology are burdened with the names of many 

 fragmentary fossils, types of species practically unknown. 



Among the vertebrates of the past, the case is much more 

 serious, and here especially reform in methods is a pressing 

 necessity. From the nature of the case, the older extinct forms 

 are usually represented by fragmentary remains, the investigation 

 of which is one of the most difficult problems offered to natural 

 science. A single tooth or a vertebra may be the first specimen 

 brought to light in a new region, and thus become the sole repre- 

 sentative of a supposed new form. The next explorer may find 

 more perfect fragments of the same or similar forms, and add new 



