Le Conte on the Pselaphide of the United States. 65 
It affords me much satisfaction, through the kind liberality 
of my friends, and the great facilities enjoyed for extensive 
exploration in distant portions of our country, to remedy in 
part this defect, at least in the little group herein treated of. 
Having made them special objects of search for the last two 
or three years, I have been most abundantly repaid by the 
discovery of many new forms. As will be seen in the sequel, 
no less than seven genera are added to those already so well 
defined in Aubé’s beautiful essay, (Annales de la Soc. Ent. 
de France, 2d ser., tom. 2.) New species have also been 
discovered of five other genera, not as yet published as inhab- 
iting our continent. So successful has been the limited ex- 
ploration, that our Pselaphidz are already nearly as numerous 
as those in Europe, and embrace a greater number of distinct 
genera. For the benefit of the American student to whom 
the memoirs of Aubé may not be readily accessible, 1 have 
reproduced descriptions of all his species which remain un- 
nown to me, while those in my possession have been care- 
fully re-described, for the purpose of bringing out more prom- 
inently the characters in which they differ from species since 
discovered. Of the generic diagnoses I will only say, that 
they too, are drawn exclusively from American species; the 
European student must not therefore be surprised if minute 
differences should be found between the descriptions herein 
given, and those already published from the European ana- 
logues. In very few of the genera of Pselaphide are the 
minute relations of the cephalic organs preserved without 
variation through an entire genus; and thus the palpi of the 
Tyrus I have described, will be seen to differ appreciably from 
Aubé’s description. I would also invite the attention of for- 
eign observers to the fact, that the antenne of the genus Bry- 
* Having had no opportunity of observing the European species of such genera, I 
Prefer taking this course, allowing my deseri ptions to differ slightly ! from these 1 si 
tofore published, to having th 
descriptions, or so modifying them as to include the | species of both continents. 
Since the differences are now pointed out in these instances, it will be easy for any 
one by foes inspection of the foreign species, to perceive where these alterations 
tidem B. S. N. H. 9 SEPT. 1949. 
