252 On Generic Nomenclature. 



perhaps, an important link in my chain of evidence, as he 

 there first distinctly named the type ; and it prejudiced my 

 argument, instead of Mr. Westwood's ; and, therefore, he was 

 not justified in calling it a partial view of the case. After 

 noticing this omission, he says, " he does not attempt to in- 

 validate my principle ;" viz. that an author has no right to 

 change a name he has once given, " without good reasons." 

 Certainly not. I support it as a good and a sound principle, 

 as I have shown above, and that it ought to be strictly ad- 

 hered to ; but, where such capricious changes are made, they 

 ought to be reprehended at the time, and not after a lapse of 

 years, when such reforming Quixotism would introduce more 

 confusion, by proceeding to correct delinquencies that are 

 already grey, than it should be its earnest endeavour to pre- 

 vent. Entomological law should, like the statute law, have a 

 period beyond which it can take no cognisance, or, I fear, we 

 shall not know where we are. Why did not Mr. Westwood 

 correct St. Fargeau and Serville in the instance adduced by 

 him of the Musca pipiens (Xylota of Meigen) ? Is not the 

 establishment of a generic name in the Diptera upon such 

 easy conditions as sure a guarantee of immortality, as may 

 be compassed by thrusting Mr. Curtis on one side in the 

 Hymenoptera, pushing Latreille into his place, justling 

 Jurine into the situation of Latreille, and then very de- 

 murely getting into Jurine's warm seat? There are many 

 reforms he can introduce upon this principle; but he cannot 

 always substitute his own names ; although, in some instances, 

 he may. In the present, he is certainly at fault : yet, whether 

 his name must not stand in lieu of Jurine's, is, perhaps, a 

 question of courtesy, rather than of right ; but, even if so, 

 it was, I think, my privilege to name it, as I had laboriously 

 worked out the entire group ; and he should have had the 

 civility to allow me to do so, instead of interpolating his 

 Dineurus. I will just examine how this stands, and then pro- 

 ceed with Pemphredon, in which I still dispute the question 

 with him, and shall show that he is wrong as to the original 

 type, Latreille's citation in the Genera having misled him. 



With regard to Cemonus, I will copy verbatim what I 

 have said upon it in my Essay on the Fossorial Hymenoptera, 

 that Mr. Westwood may not captiously take an objection, by 

 presuming that 1 beg the question by endeavouring to preju- 

 dice the reader. It thus runs : — 



" This genus was formed by Jurine for the insects which 

 Latreille had previously named Pemphredon, and which he 

 (Jurine) divided into two families : it consequently fell into 

 a synonyme of that genus, as they stood prior to my separa- 



