1935 ] 
Notes on Mycetophilidx 
89 
this country of this species, the hypopygium (fig. 2) is pic- 
tured. Taken in Ithaca, N. Y. Nov. 1934. 
Exechia aviculata sp. n. (PI. VI, Fig. 3.) 
Male. Length 4 mm. Head brown, palpi and antennae 
light brown, basal two joints of antennae yellowish. Thorax 
brown, humeri not tinged with yellow. Abdomen brown, 
the last three segments somewhat darker. Coxae and femora 
with a brownish cast, tibia and tarsi yellow. Prothoracic 
basitarsus about one fourth longer than tibia, tibia swollen 
at the apex. Hypopygium (fig. 3) light brown resembling 
somewhat that of Exechia januarii Lunds. Type locality, 
Ithaca, New York. Type in my collection, paratype in 
Cornell University collection. 
Exechia pollex sp. n. (PI. VI, Fig. 4.) 
Male. Length 3.5 mm. Head dark brown, palpi and an- 
tennae brown, basal two segments of the antennae light. 
Thorax dark brown, humeri with a light yellowish tinge. 
Abdomen concolorous, dark brown. Coxae and femora yel- 
low, tibia and tarsi somewhat darker. Prothoracic basitar- 
sus and tibia subequal in length. Hypopygium (fig. 4) re- 
sembles that of Exechia frigida but differs in the details of 
the claspers. Type locality, Ithaca, New York. Type in my 
collection. 
Rhymosia triangularis sp. n. (PI. VI. Fig. 5.) 
Male and female. Length 4-4% mm . Head pale brown, 
palpi and basal two joints of antennae yellow, remainder of 
antennae brown. Mesonotum brown, lateral margins some- 
what lighter. Coxae and femora yellow, femora slightly 
darkened at apices. Tibia and tarsi brownish yellow. Pro- 
thoracic basitarsus about a third longer than the tibia. Dor- 
sum of first and sixth abdominal segments brown. The re- 
maining segments with subtriangular brown spots with the 
apex of each segment as the base of the triangle. Hypo- 
pygium (fig. 5) yellow, resembling that of Rhymosa inflata 
but one of the arms of the forceps is much more slender. 
Type locality, South Bethlehem, New York. Type in my 
collection, paratype in Cornell University collection. 
