A. A. GIRAULT. 257 



being decidedly longer than the pedicel, not so in ameri- 

 camis ; also in general coloration. This is the first species 

 described from North America but a number of other un- 

 described forms are known to me, most of which I describe 

 beyond. 



I have since examined the type of Gonatocems aviericamis 

 Brues through the ready kindness of Dr. S. Graenicher of the 

 Milwaukee Public Museum and through the courtesy of the 

 director of that institution and it is found to differ further 

 from this species in being smaller, much less robust, in hav- 

 ing a shorter proximal tarsal joint of the posterior legs, a 

 shorter marginal vein of the fore wings and narrower fore 

 wings ; also the posterior wings are narrower and the mid- 

 longitudinal line of discal cilia is short and distad. The spe- 

 cies amcricamis is closely allied with anthonomi but differs 

 from it in being darker (a minor characteristic here), in hav- 

 ing the first three funicle joints of the antennse unequal, 

 about equal in anthonovii and by lacking the yellowish streaks 

 on the mesoscutum. The diagnostic table of the North 

 American forms of this genus, in which is included the fol- 

 lowing new species, will aid, I hope, in making the character- 

 istics of all of the species stand out more clearly. The fifth 

 North American species to be discovered is described here- 

 with, upon which the descriptions of other common species 

 are given. 

 2. Gonatocems rivalis species nova. 



Normal position. 



Female. — Length, 1.00 mm. Moderate in size for the genus and 

 with the usual habitus but more slender and graceful, the ovipositor 

 together with its valves exserted for about a fourth or more of the length 

 of the abdomen. 



Black, the base (nearly basal third) of the abdomen contrasting by 

 being pallid yellowish, yellowish brown or chrome yellow or orange. 

 Base of the valves of the ovipositor (at the tip of the abdomen) , inter- 

 mediate and posterior coxae and trochanters, tarsi, cephalic trochanters 

 and posterior femora (the latter nearly) concolorous with base of the 

 abdomen ; antennal scape and pedical varying by being suffused more 

 or less with pallid, especially ventrad on the scape, the remaining por- 

 tion of the antennse black ; knees and tips of the tibiae more or less 

 pallid as are also most of the cephalic tibiae ; distal tarsal joint in- 



TRANS. AM. ENT. SOC, XXXVII. (33) 



