l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 73 



ses. Some diagnoses have been unintelligible to the author's contem- 

 poraries, and have been proved by subsequent reference to the type 

 specimens to be misleading and even incorrect. 



The object of a definition or diagnosis is to furnish contemporary 

 fellow-workers with the characters by which they can distinguish the 

 species from others already known or diagnosed at the same time. It 

 is not (as is a description) intended to furnish evidence by which the 

 species may possibly be distinguished from all others hereafter to be 

 discovered. It is when extension and precision of the original diagno- 

 sis are necessitated by further discoveries that recourse to the holo- 

 type is incumbent on the reviser. If contemporaries could not under- 

 stand a definition apart from the holotype, it is surely plain that the 

 definition was inadequate from the outset. Since there always was 

 and must be type material of some kind, the logical consequence of 

 inclusion of the holotype itself within the definition would be to de- 

 prive the rest of the definition of any significance. One need say no 

 more than : "A charming species, rather large, Holotype : Nat. Mus. 

 Ruritaniae, No. X999." 



Dr. Richter supports his thesis by an appeal to the " subjectivity " 

 involved in any interpretation of the diagnosis. A bad diagnosis 

 undoubtedly opens the door to subjectivity ; but a diagnosis is good in 

 so far as it eliminates subjectivity. After all there may be as much 

 subjectivity in the interpretation of a holotype (especially if it be an 

 obscure fossil) as in the reading of a diagnosis. (See next Section, 

 argument No. 6.) 



The arguments in favor of the proposal are contained to some ex- 

 tent in the original application (C. and A.), but still more in letters 

 subsequently received from Mr. Cox (C.) and Mr. Arkell (A.). 

 They are : 



1. The comments of d'Orbigny are inadequate as specific diagnoses 

 (C. and A.). 



2. D'Orbigny's species have been misinterpreted by later authors, 

 or have been ignored and described under other names (C. and A.). 



3. The names, whether d'Orbigny's or new, used by later authors 

 are familiar and current, and it would breed confusion to disturb them 

 (C. and A. and A., who gives many examples). 



4. D'Orbigny was a competent describer, not to be compared with 

 writers 50 years before him. and he himself says that it is not his 

 intention to describe the new species in the " Prodrome " ; he would 

 have described them later in the " Paleontologie Franqaise " (C). 



5. Reference to a type specimen should not be a permissible substi- 

 tute for an intelligible definition (C). 



