288 APPENDIX A. 



tendency to appear at irregular intervals. I suppose it will not be 

 doubted that Herrich-Schaffer's work was properly published, but 

 this appeared at all sorts of dates (vide HS. CB. Regensbiirg 1869), 

 and the same remark equally applies to the Biologia Centvali- 

 Ainericana and all such works\ The authors of the British Asso- 

 ciation code laid down the following rule : — 



'§12. A name which has never been clearly defined in some 

 published work should be changed for the earliest name by which 

 the object shall have been so defined,' and they previously remark, 



' Definition properly implies a distinct exposition of essential 

 characters ; and in all cases we conceive this to be indispensable, 

 although some authors maintain that a mere enumeration of the 

 component species, or even of a single type, is sufficient to authenti- 

 cate a genus.' 



No one will be disposed to doubt the necessity for full defi- 

 nition of all genera published after the acceptance of the British 

 Association Rules, but it was impossible for authors who lived and 

 died before these rules were made known to act up to them. All 

 previous work must be tested by the meaning of the word 'defi- 

 nition.' Definition does not consist of a generic term accompanied 

 by a greater or less number of mere words which are not diagnostic 

 (e.g. the majority of Walker's genera in the British Museum Cata- 

 logues), but 'definition' means that the genus proposed shall be 

 capable of comprehension, Hiibner's works exemplify the two 

 types of genera. In the Tentameii we have genera which are 

 readily understood, for the type is always cited: we turn to Hiibner's 

 figure and can ascertain what species was intended, and for our- 

 selves test whether the genus be valid or not ; on the other hand, 

 in the Verzeichniss the generic name is accompanied by what out 

 of courtesy is called a diagnosis: these genera are for the most part 

 composed of incongruous material and it is impossible to ascertain 

 what was the original type of the genus, but they are accompanied 

 by some 'verbiage,' and if we follow the British Association ruling 

 they must be accepted, whereas from a scientific point of view the 

 Teiitavien genera, being monotypical and capable of absolute identi- 

 fication, are much more worthy of recognition. 



Citation of type is practically equivalent to definition, for anyone 

 can understand what was intended by an author like Hiibner, who 

 figured all the species with which he was acquainted. I am there- 

 fore disposed to think that Hiibner's Tentamen genera comply with 

 the requirements of 'definition,' and as they were 'published' we 

 are bound to accept them. 



The requirements of § 2 of the German Zoological Society, 

 'Als wissenschaftlicher Name ist nur derjenige zulassig, welcher in 

 Begleitung einer in Worten oder Abbildungen bestehend und nicht 



^ In these works each part was published at a definite date, but Hiibner, by Geyer's 

 account, kept his type set up and printed off and issued a few copies whenever there was 

 a demand for them. G. F. Hampson. March 1899. 



