14 NOMENCLATURE. 



Can we carry out successfully any laws of nomenclature ? Must we not 

 always be guided, when treating special cases, by the practice current at 

 any .given time ? Have we the right to introduce distinctions unknown at 

 the time of Linnaeus, of Klein, of Leske, for the sake of harmonizing the 

 past with the existing condition of our knowledge? When Leske says his 

 Cidaris esculeiita is the Echinus escukntus of Lin., we can only say that, 

 from what we know now, after examination of authentic specimens, they are 

 different species, even belonging to different genera; such a comparison 

 forms a substantial basis for the correctness of our recent specific names. 

 When we come to apply the same rule to genera, the case is not so simple. 

 Is it advisable to restore Echinanthus Klkix. as Gray has done, to the 

 exclusion of Clypeaster of La.mk., when the exact limits of the genus as 

 understood by Breynius and by Lamarck show that although they included 

 many identical species, yet they were by no means equivalent? We cannot 

 afford to lose from the history of the order the early names, but we had 

 better lose them if we are to introduce them at the cost of making endless 

 confusion by giving them definite meanings their originators did not intend 

 them to have. We can, without injustice to subsequent workers, frequently 

 keep both names; but I claim that where a name is not used in the same 

 sense in which the originator intended it, it should not be preserved and 

 substituted to exclude subsequent names representing distinctions and differ- 

 ences of which the original writer could not have been aware. 



Echinoconus Bkeyv, Echinanthus, Echinospatagus, Echinobrissus, need 

 not be used to the total exclusion of Lamarck's names or of more than one 

 of the genera into which Echinoconus, etc. has been subdivided subse- 

 quently ; yet if afterwards any writer limits Echinoconus, etc., such limita- 

 tion can always be understood or stated, and the old name retained for a 

 section at least of the many genera each is composed of. I claim that writ- 

 ers who mentioned as type of a genus certain species did not attach to 

 it the significance we now do; they used it as an iUustraium of what they 

 meant by taking a well-known thing, and the very fact that they frequently 

 made the type of their former genus the type of another, leaving to the 

 first only other species either originally included or subsequently added, 

 sufficiently shows what was the current opinion of the nature of a genus at 

 that particular period. The fact is, that our species stand very much in the 

 relation of a variable of which we are constantly (or were up to a compara- 

 tively recent date) attempting to state the value by means of constants. 



