,844—185^] NOMENCLATURE 69 



I thank you sincerely for your very kind offer of occa- Letter 30 

 sionally assisting me with your opinion, and I will not 

 trespass much. I have a case, but [it is one] about which 1 

 am almost sure ; and so to save you writing, if I conclude 

 rightly, pray do not answer, and I shall understand silence as 

 assent. 



Olfcrs in 1814 made Lepas aurita Linn, into the genus 

 ConcJioderma ; [Oken] in 1815 gave the name Branta to Lepas 

 aurita and vittata, and by so doing he alters essentially 

 Olfers' generic definition. Oken was right (as it turns out), 

 and Lepas aurita and vittata must form together one genus. 1 

 (I leave out of question a multitude of subsequent synonyms.) 

 Now I suppose I must retain Conchoderma of Olfers. I 

 cannot make out a precise rule in the British Association 

 Report for this. When a genus is cut into two I see that the 

 old name is retained for part and altered to it ; so I suppose 

 the definition may be enlarged to receive another species — 

 though the cases are somewhat different. I should have had 

 no doubt if Lepas aurita and vittata had been made into two 

 genera, for then when run together the oldest of the two would 

 have been retained. Certainly to put ConcJioderma Olfers is 

 not quite correct when applied to the two species, for such 

 was not Olfers' definition and opinion. If I do not hear, I 

 shall retain Conchoderma for the two species. . . . 



P.S. — Will you by silence give consent to the following ? 



Linnaeus gives no type to his genus Lepas, though L. 

 balanus comes first. Several oldish authors have used Lepas 

 exclusively for the pedunculate division, and the name has 

 been given to the family and compounded in sub-generic 

 names. Now, this shows that old authors attached the name 

 Lepas more particularly to the pedunculate division. Now, if 

 I were to use Lepas for Anatifera' 1 I should get rid of the 

 difficulty of the second edition of Hill and of the difficulty 

 of Anatifera vel Anatifa. Linnaeus's generic description is 

 equally applicable to Anatifera and Balanus, though the latter 

 stands first. Must the mere precedence rigorously outweigh 



1 In the Monograph on the Cirripcdia (Lepadidae) the names used 

 are Conchoderma aurita and virgata. 



2 Anatifera and Anatifa were used as generic names for what Linnaeus 

 and Darwin called Lepas anatifera. 



