1880.] 379 [Patton. 
Pelopoeus, the mandibles of the males are unarmed, slender and 
acute. 
This genus affords an interesting example of the value of color as 
a generic character. Separated from Pelopoeus by Dahlbom in 
1843 (Hymenoptera Europaea), it was rejected by him two years 
later in the supplement of the same work, and no characters aside 
from color were discovered to distincuish it. No subsequent author 
has discovered additional characters, or has ventured to reéstablish 
the genus. The characters which I have given above, however, 
prove that the distinct coloration was a sufficient generic indication. 
As Dahlbom indicated no type, I select the common American 
species. In Ch. caerulewm ¢ there are two small teeth on the cly- 
peus in addition to the three central ones, the margin of the third 
ventral segment is sinuate, and there are tomentose spots on the 
third and fourth ventral segments (Dahlbom stated that these 
spots were on the second and third segments). PP. californicus 
Sauss., said to differ from caerulewm in the slightly shorter petiole, I 
do not consider distinct. I have before me ¢ and ? specimens 
from California which agree in all respects with Ch. caeruleum. 
Ch. Zimmermanni Dahlb. ? differs from Ch. caeruleum in the fol- 
lowing characters: clypeus tridentate, no side teeth; third ventral 
segment not sinuate, and the third and fourth without any black 
sericeous spot; punctures of head and thorax distinct, not confluent, 
no median elevated line on clypeus or front; no median sulcation on 
disk of metathorax; face narrower beneath, mandibles broad and 
blunt, and with a broad and blunt tooth near the apex; mandibles 
shorter than in either Ch. caeruleum or Pelopoeus. 
To Chalybion belong also Ch. texanum (P. texanus Cress.), and 
Ch. aztecum (P. aztecus Sauss.). 
CHLORION Latr. 
Edge of the clypeus with three teeth in the male, and five teeth in 
the female. Mandibles armed with a stout tooth in both sexes. 
Sutures of the meta-episterna distinct. Claws of all the tarsi armed 
with one tooth. Spines of anterior tarsi of no longer than the 
fourth tarsal joint. Labrum short and transverse as in Chalybion 
and Pelopoeus. 
After carefully studying the arguments given by Westwood, 
Trans. Ent. Soc. Lond, iii, 227-230 (1840), it remains evident that 
as Latreille confounded two very distinct genera in his genus Chlorion, 
and as his views as to the type of the genus were originally confused, 
