80 THE NAUTILlJg. 



I think it is recognized by all who have at all carefully studied 

 the family that Dr. Lea's arrangement, classifying by the presence 

 or absence of a dorsal wing, by sculpture and form, is largely 

 artificial and that some more natural system should be adopted. I 

 believe that the subgenera of Rafinesque, Swainson, Agassi/, and 

 others are of little value; it seems to me that an arrangement into 

 groups around certain characteristic and fairly typical species is the 

 most natural that can be made. But while there are large numbers 

 of species among which the strongest relationship is at once apparent 

 there are many others which seem to stand on the border land, and 

 which may as well be placed in one section as another ; others, by 

 the characters of certain specimens, appear to have an affinity in one 

 direction and by those of others to belong elsewhere, while there 

 are some nondescripts that do not fit anywhere. 



It is my intention to publish some time in the future a Geographic 

 and Systematic Catalogue of the Unionidte of North America, but it 

 will require years of patient study to prepare it. I also hope at 

 some time to be able to monograj)h our species. 



So far as the South American forms are concerned our material 

 and knowledge are so limited it seems to me it would be almost 

 unwise to attempt at present to do anything with them. Dr. von 

 Ihering is doing excellent work with the Unionidie of this region 

 and probably has a better understanding of the subject than any 

 man living. 



ON THE EEVISION OF THE UNIONID^. 



BY S. HART WRKJHT AND BERLIN H. AVRKiHT, PENN YAN, N, Y. 



Editor Nautilus : — In the September number of The Nautilus, 

 the specialists in Unionidoe are asked to reply to a suggestion that a 

 Committee be appointed to classify and revise the nomenclature of 

 the American Unionid.ie. 



It is well known that the history of this branch of (Jonchology is 

 somewhat tainted with personal bitterness and rivalry. The nomen- 

 clature is in consequence slightly chaotic ; and the synonymy though 

 not more extensive than in the Helice.«, or in Botany or Ornithol- 

 ogy and many other sciences, still needs sifting out. A classifica- 

 tion too, still better than Lea's if possible, should be brought for- 



