1911] Aldrich — North American Species of Hydrophoriis 65 



Front coxae with a row of about sixteen black bristleS on front side, more slender and 

 delicate above, and with rather dense hairs on the mesial side of the row; femora and 

 tibiae somewhat shining green, the former only moderately thickened at base, below 

 with a scattering row about ten short spines on the inner side, extending the 

 whole length, and on the outer side six or seven forming a row on the basal half; 

 tibia with a row of spines on the inner side, not erect nor enlarged at tip, and the 

 tibia is not bent toward the femur at apex. The middle and hind femora bright 

 green, rather slender. Wings a little infuscated, with black veins, a slight cloud 

 on the hind crossvein, not very apparent but constant. Abdomen showing a little 

 green above, the sides of the two basal segments with rather woolly brown hair; 

 hypopygium mostly concealed. Length, 4 mm.; of wing, 4.9 mm. 



Female. All that I have seem to have the abdomen shortened in drying, other- 

 wise not differing from the male. Length 3.6 mm.; of wing, 5.1mm. 



Fourteen specimens both sexes: Franconia and Crawford's, 

 New Hampshire, (Mrs. Slosson); New Haven, Conn,, Oct. 21, 

 1903 (C. W. Johnson, collected by H. L. Viereck); Danvers, 

 Mass., Sept. 23 (C. W. Johnson); Montreal, Que., Sept. 1, 1901 

 (G. Beaulieu). 



In some specimens there is a distinct metallic reflection on the 

 upper half of the face when the light comes from straight in front 

 or a little below. 



Hydrophorus extrarius sp. nov. 



Female. Occiput moderately shining green, with one pair of postverticals; post- 

 orbitals about fifteen, descending hardly to the middle of the eye; cheek very 

 narrow, beard white; no black bristles below the neck; front brownish pollinose, 

 in some lights dark greenish; face rather narrow for the sex, somewhat pollinose all 

 over, yet on the upper, concave part a dull green shows through the brown dust; 

 lower convex part of the face with dense brown dust in the middle, and whitish 

 on the sides; palpi gray, with mixed whitish and black hairs; antennae of plain 

 structure, a little longer than in some species. Thorax rather seal brown above, 

 brighter green behind; at the notopleural suture this changes to glaucous; scutellar 

 bristles two pairs, notopleural two, humeral two rather small, dorsocentrals fairly 

 well developed but slender, acrostichals except at extreme front of the same size 

 as the last. Propleura with white hairs and one black bristle; stemopleura with 

 only a few microscopic pale hairs; squama yellow with whitish hair; hal teres yel- 

 low, with a large brown spot on the knob. Front coxae glaucous, with dense, short 

 white hair in front and no black spines except two or three short ones at the tip; 

 front femur not very much enlarged, below with a short row of five or six spines 

 on the outer side at base and another short row on the inner side toward the tip 

 (in one specimen a few small scattering spines continue this inner row toward the 

 base more than in the other one) ; front tibia straight, with the usual row of small 

 spines on the inner side quite slanting, not enlarged toward tip; middle and hind 

 femora rather slender and a little bowed; wings almost hyaline, imspotted, veins 



