NO. 8 OPINIONS 124 TO 133 21 



a new species ; they believed that their specimens belonged to d'Or- 

 bigny's species. If the contrary cannot be proved, surely the name may 

 be left. 



Many of the difficulties arising out of the " Prodrome " and simi- 

 lar works would be largely smoothed away if the Commission could 

 agree to the following : 



A name that rests on a diagnosis unintelligible in itself and not 

 explained by the type material, shall not prevent the use of the same 

 name for a species from the same locality and horizon, when sulise- 

 quently diagnosed in proper form. 



To meet the undoubted difficulties I have endeavored to frame an 

 Opinion that would be of general application, but without success. I 

 therefore submit the following for the approval of the Commission. 



Opinion. — There are no grounds for treating d'Orbigny's " Pro- 

 drome " differently from other works containing preliminary diag- 

 noses. In all such cases the decision whether a diagnosis is adequate 

 or no must be made by the systematist and not by the Commission. 



If the diagnosis is held to be adequate, the ordinary rules regarding 

 priority and homonyms apply. 



If the diagnosis is held to be inadequate, tlie publication of the name 

 will not prevent any author from subsequent description and estab- 

 lishment under the same name of the same species (as recognised from 

 the holotype, if any) ; further, if the holotype be wanting or unde- 

 cipherable, subsequent description and establishment under the same 

 name of a species from the same locality and horizon is permissible. 

 In both these cases the date for purposes of priority shall be the later 

 date, and if the later author (say Brown) is not the same as the 

 earlier author (say Green) then the name shall be quoted as " Brown 

 ex Green ". If, however, the holotype attached from the beginning 

 to the earlier use of the name with inadequate diagnosis be clearly 

 of a different species from the holotype attached to the later use, 

 then the later use is a homonym as defined by Article 35 and is to be 

 rejected. 



On the question of generic names, also raised by the applicants, 

 Dr. Adensamer considers that a genus if properly diagnosed will be 

 valid although the species referred to it may be suppressed as noiiiiiia 

 nil da. 



This seems rather a contradiction in terms. 



If there is only one species, the diagnostic features of the genus, 

 which ex hypothesi are adequate, will also distinguish the species. 1 f 

 neither they nor the characters of the species are adequate, then both 

 genus and species must fall. (Cf. Opinion 43.) 



