532 Mr. R. I. Pocock on Pherusa fucicola, Leach. 



stand as a genus and species of which GammareJla brevi- 

 caudata, Normanni, &c. are synonyms ; (2) that Amphithoe 

 Jurinei must be the name for the species which Bate in 1862 

 described as P.fucicola. 



Having thus extricated ourselves, let us turn back for a 

 moment and follow Mr. Walker along his path. His choice 

 of it has evidently been taken in the hopes that it will enable 

 him to circumvent the ruinous edifice of synonymy which 

 blocks the way on the highroad ; perhaps, too, he has been 

 influenced by the thought that he will thus shift the respon- 

 sibility of pulling it down upon some one with less regard 

 for his own head than he has himself. 



So much for his reasons : now for his excuse. 



It sometimes happens that an author will, for the sake of 

 peace and quietness, abstain from upsetting a recognized 

 system of names, although he knows it to be rotten to the 

 core, excusing himself on the trumpery plea that the correct 

 name for an object is the name that has been most often 

 used for it or that by which it is most commonly known *. 

 But, to do Mr. Walker justice, he shelters himself 

 under no such flimsy a covering as this. He boldly meets 

 on their own ground those who attack him with the law 

 of priority, brandishing in their faces another rule of the 

 British Association. This rule, as he has told us, is in sub- 

 stance this : — No name can acquire authority until it be 

 defined, definition being the distinct exposition of essential 

 characters. 



But what on earth does this mean? It is a thousand 

 pities that the compilers of the rule did not give a distinct 

 exposition of the meaning of the word essential. Essential 

 for whom? and for what time? For Linnajus? for Mr. 

 Walker ? or for the zoologist of a hundred years hence ? A 

 knowledge of what is essential is purely a matter of expe- 

 rience. Therefore what is essential to-day may be absolutely 

 inessential to-morrow ; and consequently, in accordance with 

 the rule, the names that are given in the nineteenth century 

 may all have to be abolished in the twentieth, just as those 

 who adopt and revere the rule (which I do not) must rechristen 

 almost every species constituted by Linnasus. For it is 

 scarcely an exaggeration to say that he who adopts a Linncean 

 name tacitly ignores the rule. 



1814 description applies to the types and the 1815 one does not. At all 

 events, I should be sorry for it to fall to ray lot to refute such a belief. 



* In that case a schoolboy should be designated in the roll-call by his 

 nickname. 



