No. 22.] HYMENOPTERA OF CONNECTICUT. 59 



Monosoma MacGillivray. 

 *M. inferentia (Xorton). Pacilostoma inferentia Norton. 



Female rufous, with the following parts black: head except 

 clypeus and labrum, antenna, metathorax and saw-guides; with 

 the following parts white : labrum, tegulae, collar, and a fine line 

 on the apex of each abdominal segment ; third segment of antennse 

 as long as fourth and fifth together; median fovea and ocellar 

 basin continuous. Male differs in having head, thorax, and ab- 

 domen black, and legs dark rufo-fuscous. Length 8 mm. Larva 

 feeds on alder. 



Farmington (E. N.). 



Macremphytus MacGillivray. 



Key to Species. 



1. Antennae either black or rufous at base and white at apex, 



or entirely black 2 



Antennae with four basal segments rufous and five apical seg- 

 ments black; body in female rufous, with the following 

 parts white : labrum, apices of coxae, trochanters, a band at 

 the base of tibiae, metatarsi in part, and basal half of 

 stigma; with the following parts black: five apical seg- 

 ments of antennae, antennal furrow and ocellar basin, 

 lateral portion in part and ventral portion of prothorax, 

 lateral lobes of mesonotum, metathorax in part, coxae, basal 

 half of anterior and middle femora, the posterior femora, 

 and the apex of posterior tibiae; antennae with third seg- 

 ment longer than fourth, fourth and fifth subequal; head 

 with the ridges forming the side of ocellar basin parallel, 

 and with the area between lateral ocelli distinctly depress- 

 ed; postocellar area without a furrow; saw-guides straight 

 above and gradually sloping toward the apex where they 

 are obliquely rounded to a point above. Male differs in 

 having the greater part of head and thorax black and the 

 greater part of legs beyond coxae white or rufous. Length, 

 8-10 mm semicomis 



2. Antennal furrow not as deep opposite the anterior ocellus as 



elsewhere, and with a supernumerary furrow extending 



obliquely from the antennal furrow toward the eye 3 



Antennal furrow of the same depth throughout and with- 

 out an oblique supernumerary furrow 4 



3. Thorax in great part black with rufous markings; head with 



the raised area between lateral ocelli flat and broken at 

 center by a line-like furrow; ocellar furrow distinct; ocel- 



