xiv PREEAOE. 



repetition of the same name as generic and specific, and also in order to preserve 

 the right of priority of the original specific denominations. It is an excellent rule, 

 but it must not be enforced so as to take retrospective effect, it would cause enor- 

 mous confusion in our nomenclature, and nothing would practically be gained by it. 

 Indeed, I doubt whether it ever would become generally acknowledged. A date 

 should be specified, from which the rule should come into force, and this time 

 should be communicated to all scientific bodies in Europe and abroad : and there is 

 little doubt that in this manner generally applicable results would be obtained. 



E. STOLICZKA. 



