INTRODUCTION. 9 



wider acceptation of the terms proposed by Thomas, Schuchert, and 

 Cossmann. In regard to the desirability of type terms, Bather" states: 



This * * * shows how necessary the definition of these terms has become. 

 It also exemplifies a danger that needs constant guarding against, namely, the 

 employment of a common word in a restricted * * * sense. The man in the 

 street knows the meaning of "type" and "typical," but the meaning of those terms 

 to the zoologist is something quite different. 



The following classification of type specimens is an expression of indi- 

 vidual opinion, in the hope that biologists will, when necessary, emend 

 the different definitions here given or offer new ones, so that a proper 

 terminology in regard to type specimens may come into general use. 



CLASSIFICATION OF TYPE SPECIMENS. 



All type specimens in biology may be divided into two groups — type 

 material and typical specimens. 



Type material includes all specimens which have served as the basis 

 for published primary and supplementary descriptions and figures of 

 organisms. These are again divisible into two sections — primary and 

 supplementary types. 



Primary types, or ProTerotypes. — These are the original speci- 

 mens of any described or figured new species. In a letter to the writer, 

 Buckman has proposed for the English term the collective name Pro- 

 Terotypes. They are usually referred to by zoologists, botanists, and 

 some paleontologists as ' ' types. ' ' Primary types are again divisible 

 into holotype, cotype (or syntype), paratype, lectotype, and 



CHIROTYPE. 



Supplementary types. — These consist of the described or figured 

 specimens used by any author in supplementing or correcting knowledge 

 of a previously defined species. This section is divisible into PLESio- 

 Type, neotype, and heautotype. 



Typicae specimens, or Icotypes. — These have not been used in pub- 

 lished descriptions or figures, but consist of material which authors have 

 worked on or such as has been or can be collected at the original locali- 

 ties of new species. In a letter to the writer, Buckman proposes for 

 these types a good collective term — Icotypes, meaning that which is 

 like, probable (= types having resemblance to proterotypes). Typical 

 specimens are divisible into Topotype, metatype, homcEOType, and 

 IDEOTYPE. 



Besides ' ' type material ' ' and ' ' typical specimens ' ' there are other 

 entities of a type nature to which authors have seen fit to apply a termi- 

 nology. Such are "type drawings," "reproductions of type speci- 

 mens," "type species of genera," and "types of organisms in relation 

 to geographic distribution." These will be defined further on. 



a Science, May 28, 1897, p. 843. 



