98 KINCAID [358] 



sutures of tergum, and narrow lateral margin of abdomen, light yel- 

 low; pectus and pleura, except a black spot beneath wings, yellow; 

 face below antennae and venter of abdomen, white; legs yellowish 

 white ; wings hyaline, nervures dark brown, stigma and costa hyaline. 



One female, Yakutat, Alaska, June 21, 1899. 



Type no. 5305, U. S. National Museum. 



Allied to Pteronus vertebratus Say, but in that species the head is 

 broadened behind the compound eyes. 



PTERONUS RIVULARIS sp. nov. 



Male: Length 7 mm.; slender, shining; clypeus narrowly and 

 deeply emarginate, lobes rounded ; walls about ocellar basin distinct 

 but not sharply raised ; frontal ridge broken in the middle into the 

 shallow, narrow, antennal fovea ; antennae considerably longer than 

 head and thorax, flattened at base, tapering graduallly to apex, third 

 joint much shorter than fourth or fifth, which are subequal ; procidentia 

 scarcely produced, truncate ; venation normal ; stigma narrow, rounded 

 at base, tapering to an acuminate apex ; claws not very deeply cleft, 

 inner ray shorter. Color black; clypeus, labrum, apex of coxae, 

 trochanters, apex of anterior femora, and anterior and middle tibiae, 

 whitish ; wings smoky hyaline, nervures, including stigma and costa, 

 dark brown. 



Two males, Sitka, June 16. 



Type no. 5304, U. S. National Museum. 



Allied to Pteronus iridescens Cresson, but that species is smaller 

 and the antennae are much shorter. 



AMAURONEMATUS ISOLATUS sp. nov. 



Female : Length 10 mm. ; robust, covered with a dense sericeous 

 pile ; clypeus deeply .and triangularly emarginate, lobes triangular, 

 acute; walls of ocellar basin sharply raised ; frontal crest bituberculate, 

 deeply notched in the middle; antennal fovea minute, indistinct; 

 antennae as long as the head and thorax, stout, scarcely tapering, third 

 joint shorter than fourth ; second recurrent nervure nearly interstitial 

 with second cubital ; stigma narrow, broadest near base, tapering to 

 an acute point; sheath broad, obtuse at apex, rounding above and 

 below ; cerci short, somewhat constricted at base ; claws stoutly cleft, 

 innermost ray the shorter. Color ferruginous; scape, pedicellum, 

 apical joint of antenna?, spot surrounding bases of antennae, clypeus, 

 base of labrum, small spots behind posterior ocelli, line on middle 

 lobe of mesonotum, apex of scutellum, metanotum, lower angle of 



