120 Bulletin Wisconsin Natural History Society. [Vol. 7, Nos. 3-4. 



small ; first seven flagellar joints with long sparse black hairs and 

 dentate at the outer apical angle ; the base of each constricted to a 

 very thin pedicel which is as long as the joints near the base, but 

 gradually grows shorter to the seventh joint after which it is not 

 present. First flagellar joint scarcely twice as long as thick ; second 

 to fourth about quadrate ; fifth one-half longer than thick ; sixth twice 

 as long as thick ; following becoming more elongated. Mesonotum 

 about as broad as long and scarcely narrowed in front ; its surface sub- 

 opaque and faintly punctulate ; with three furrows which converge 

 toward the posterior margin where they meet the narrow impressed 

 line at the base of the axillae. Axillae meeting narrowly on the median 

 line. Scutellum broad, not very strongly convex. Metathorax very 

 short rugose. Pleurie smooth, polished ; mesopleura with a curved series 

 of punctures at its upper anterior angle. Abdomen as long as the 

 thorax, more strongly convex below than above ; petiole very short ; 

 second segment occupying nearly two-thirds of the surface of the ab- 

 domen, basally with a raised rim or margin and an extremely short 

 series of basal pits or stria?. Apical segments all very short; tip of 

 abdomen piceous. Legs brownish yellow, the posterior coxae infus- 

 cated except at their tips. Wings nearly hyaline, stigma fuscous, oval ; 

 two thirds as long as the radial vein. 



Three specimens, two from the slope of Mount Constitution 

 and the other from one of the islands in Puget Sound, without 

 more definite data. 



The present species appears to he most closely related to 

 /,. picipes, but differs decidedly from a male of this species which 

 I have from the East, by its much more strongly dentate antennae. 



The following table will aid in separating the North American 

 species of Lygocerus. 



KEY TO THE SPECIES OF LYGOCERUS. 



1. Males 2 



Females 9 



2. Antennas with the first seven joints ramose ; legs entirely red- 



dish yellow floridanus Ashm. 



Antennae serrate or toothed on the basal joints 3 



3. Flagellar joints, 1-5 or 6 dentate 4 



Flagellar joints, 1-7 dentate 8 



