32 
Psyche 
[April 
THE EUROPEAN SUBGENUS ACTEDIUM (BEMBIDION) 
IN NORTH AMERICA. 1 
By P. J. Darlington, Jr. 
In a box of Albertan Bembidion recently received for deter- 
mination from Mr. F. S. Carr, the writer found two specimens of 
an apparently undescribed species belonging to the subgenus 
Actedium Mots., a group not heretofore recorded from this con- 
tinent. Actedium, which was erected in 1864 (8) for two Euro- 
pean species, was defined as follows: elytra subquadrate (presque 
carre); the striae distinctly punctured, effaced toward the apex, 
not deeply impressed, the 7th visible, the third with two small 
foveae; head and thorax punctate, the latter cordate with the 
basal impressions feeble. It may be added that the eyes are 
prominent, the humeri indistinctly angulate, the 8th stria close 
to the margin, and the mentum tooth entire and triangular. 
The two original species of the subgenus, together with a third 
described from Europe in 1870 (6) and the one described below, 
form a homogeneous group, the habitus being like that of a very 
stout Lachnophorus. 
In comparing Actedium to our other groups of Bembidion , 
it seems best to mention the closely related European subgenus 
Princidium Mots. This was described in the same paper as Ac- 
tedium, and was separated from it chiefly by having the form 
narrower and the elytral striae entire. The two subgenera to- 
gether are equivalent to the third group of Jacquelin-Duval’s 
monograph, “De Bembidiis Europseis” (7). 
It may be noted at this point that the several American 
species included in Princidium by Motschulsky, notably those 
now listed as dilatatum Lee., honestum Say, and concolor Kby., 
have all been referred to Peryphus Steph. by Casey (1). Of the 
two European species placed in Princidium, only one, punctula- 
tum Drap., can be retained. The other, ruficolle Gyll., has a very 
different habitus and has the elytral foveae on the third interval. 
Since no genotype has been assigned for Princidium thus far, 
Contribution from the Entomological Laboratory of the Bussey Institu- 
tion. Harvard University, No. 262 . 
