ADDITIONS AND CORRECTIONS. 
It is three years since the foregoing Synopses and Descriptions were 
written. In that time additional researches and discoveries have neces- 
sitated a number of changes. These can not be made in the text. They 
appear in the Systematic List given below. The latter corrects the 
preceding wherever they differ, and expresses my views in regard to 
value of characters, classification, etc., at the latest date. Such descrip- 
tions as are lacking in the earlier work, and any changes in the text 
that may be found necessary, are placed under their proper heads in 
the List. In many cases the original diagnosis 1s somewhat closely fol- 
lowed, changes being made only when really necessary. 
At first it was the intention to devote these pages exclusively to Ken- 
tucky species. The geographical position of this State, however, being 
such as to make it a sort of neutral ground, of which none of the species 
were peculiar to itself, it was seen that it would greatly enhance the value 
of the work for Kentucky, and for the other States, to increase its scope 
so as to take in all North America from the Isthmus of Tehuantepec. 
The descriptions include nearly or quite all the species occurring north 
of the Isthmus, although a few of them are only stragglers from the 
southward: the illustrations, with but one or two exceptions, are of those 
of Kentucky. Whenever possible, individuals showing variations from 
such as may have been figured or described by others have been selected 
for illustration, with the purpose of adding to or correcting our knowledge 
of the species. 
NovEeMBER, 1882. 
