1895.1 191 



Sorhagen correctly iclcnlifiod the genus to which the mine belonged, 

 and we are indebted to him for having figured and described it, thus 

 calling attention to the fact that a new species of Heliozela = Tinagma 

 was to be found mining the birch, but the bestowal of a special name 

 upon an empty mine was an excess of energy with which science 

 could have very well dispensed, and it seems to me that this proceeding 

 was little better than the reprehensible practice of giving names to 

 figures in the absence of the insect ; the differences noticed in such 

 figures may be due to artistic imagination. Too great impatience is 

 the cause of sucb procedure, there are sufiicient new species in our 

 collections awaiting description without devoting our time to hypo- 

 thetical ones. The geologist would be justified in naming a mine in a 

 fossil leaf or the cast of an insect, because the odds are very great 

 against the insect itself being preserved and eventually coming to 

 light, but no such justification can be found for the student of existing 

 forms who gives a name to a hypothetical insect whose existence is 

 only indicated by larval traces in vegetable structure, or by a figure 

 not agreeing with an}' known form. 



The authors of the British Association Eules did not apparently 

 contemplate the possibility of such names, and as there are apparently 

 no rules for guidance, I would propose the following, which I hope 

 Avill be accepted in lieu of better : — 



1. — Special names should not be given to ih.e indications oi new species, whether 



fore- shadowed by traces in or on vegetable structure, or by the existence of 



figures not agreeing with known forms. 



(a). Names given in such cases to be treated as MS., their adoption advocated 



when the species is discovered and described, but the name to date from 



the description of the species itself, not from that of the named indication 



of its probable existence. 



Example— -J n^JSj^jVa RIviUei, Sin., should date from 1872 (Stn., Ent. 

 Mo. Mag., IX, 54-6), not from Trans. Ent. Soc. (n. s.), Ill, 89 (1855), nor 

 from Tin. S. Eur., 309-19 (1809), because in these references Stainton was 

 unacquainted with tlie insect, and had merely named Godehcu de Rivillo's 

 figures, Ihe argument being that Entomology is the study of Insects not of 

 typographical records. The earlier references should, however, be quoted 

 in brackets. 

 2. — Special names should not be given to the preparatory stages of insects. 



{a). Such names should be adopted if known when describing the imago, and the 

 authority for the larval name cited in brackets, but the name itself to date 

 from the description of the imago, the argument being that the deseriber 

 of the larva could not possibly know that the species had not already been 

 described from the imago. 



